diff --git a/.github/workflows/build_and_test_mac.yml b/.github/workflows/build_and_test_mac.yml
new file mode 100644
index 0000000..c6032a3
--- /dev/null
+++ b/.github/workflows/build_and_test_mac.yml
@@ -0,0 +1,80 @@
+name: Build and Test - MacOS
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  build:
+    name: Build flows2fim
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout Repository
+      uses: actions/checkout@v4
+
+    - name: Set up Docker Compose
+      uses: docker/setup-buildx-action@v3
+
+    - name: Run Docker Compose
+      run: |
+        docker compose up -d
+        docker ps
+
+    - name: Attach to running container and Build
+      run: |
+        CONTAINER_ID=$(docker ps -q | head -n 1)
+        if [ -n "$CONTAINER_ID" ]; then
+          docker exec $CONTAINER_ID /bin/bash -c "./scripts/build-darwin-arm64.sh"
+          docker compose down
+        else
+          echo "No running containers found"
+          exit 1
+        fi
+
+    - name: Upload Artifact
+      uses: actions/upload-artifact@v4
+      with:
+        name: flows2fim
+        path: builds/darwin-arm64
+
+  test:
+    name: Test flows2fim
+    runs-on: macos-latest
+    needs: build
+
+    steps:
+    - name: Checkout Repository
+      uses: actions/checkout@v4
+
+    - name: Download artifact
+      uses: actions/download-artifact@v4
+      with:
+        name: flows2fim
+        path: builds/darwin-arm64
+
+    - name: Add flows2fim to PATH
+      run: |
+        ls -R builds/darwin-arm64
+        sudo chmod a+x ./builds/darwin-arm64/flows2fim
+        ./builds/darwin-arm64/flows2fim --version
+        echo "builds/darwin-arm64" >> $GITHUB_PATH
+
+    - name: Install & Configure GDAL
+      run: |
+        brew install gdal
+
+    - name: Verify gdal installation
+      run: |
+        gdalinfo --version
+
+    - name: Issue flows2fim controls test cases
+      run: |
+        ./scripts/test_suite_mac.sh controls
+
+    - name: Issue flows2fim fim test cases
+      run: |
+        ./scripts/test_suite_mac.sh fim
diff --git a/INSTALL.md b/INSTALL.md
index df6b763..14eb124 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -15,7 +15,7 @@
    - The easiest way is via [**OSGeo4W**](https://trac.osgeo.org/osgeo4w/#QuickStartforOSGeo4WUsers)
 
 2. **Setup flows2fim**
-    - Go to the [**Releases**](https://github.com/ar-siddiqui/flows2fim/releases) page and download the `flows2fim-windows-amd64.zip`
+    - Go to the [**Releases**](https://github.com/NGWPC/flows2fim/releases) page and download the `flows2fim-windows-amd64.zip`
     - Unzip and copy `flows2fim.exe` into `C:\OSGeo4W\bin`
 
 3. **(Optional) Enable `gdal_ls`**
@@ -45,15 +45,15 @@
    There are various ways to install GDAL. See GDAL documentation for more details. If you are struggling with GDAL installation, consider using Docker.
 
 2. **Setup flows2fim**
-    - **Option 1. - Download**
-        - Go to the [**Releases**](https://github.com/ar-siddiqui/flows2fim/releases) page and download the `flows2fim-linux-amd64.tar.gz`
-        - Extract it and move to a directory in PATH (e.g., `/usr/local/bin`) and make it executable:
+    - **Option 1 - Download**
+        - Go to the [**Releases**](https://github.com/NGWPC/flows2fim/releases) page and download the `flows2fim-linux-amd64.tar.gz`
+        - Extract it and move to a directory in `$PATH` (e.g., `/usr/local/bin`) and make it executable:
             ```bash
             tar -xvf flows2fim-linux-amd64.tar.gz
             sudo mv flows2fim /usr/local/bin/
             sudo chmod +x /usr/local/bin/flows2fim
             ```
-    - **Option 2. - Build from source**
+    - **Option 2 - Build from source**
         - cd into root of repository
         - Build container
             - `docker compose up -d`
@@ -63,7 +63,7 @@
             - `docker exec $CONTAINER_ID /bin/bash -c "./scripts/build-linux-amd64.sh"`
         - Shutdown container
             - `docker compose down`
-        - Move executable to $PATH
+        - Move executable to `$PATH`
             - `sudo mv builds/linux-amd64/flows2fim /usr/local/bin/`
             - `sudo chmod +x /usr/local/bin/flows2fim`
 3. **(Optional) Enable `gdal_ls`**
@@ -78,3 +78,66 @@
     - Run `flows2fim --version` to confirm everything works.
     - Run `gdalinfo --version` to confirm everything works.
     - (Optional) Run `gdal_ls.py --version` if you set it up.
+
+## Mac
+
+1. **Install GDAL**
+
+    The easiest way to install GDAL on a Mac is through homebrew.
+    If [homebrew](https://brew.sh/) is not on your Mac, install it:
+    ```bash
+        /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
+    ```
+    Verify homebrew installation:
+    ```bash
+        brew --version
+    ```
+    Install GDAL:
+    ```
+        brew install gdal
+    ```
+    Verify:
+    ```
+        gdalinfo --version
+    ```
+
+   There are various ways to install GDAL. See GDAL documentation for more details. If you are struggling with GDAL installation, consider using Docker.
+
+2. **Setup flows2fim**
+    - **Option 1 - Download**
+        - Go to the [**Releases**](https://github.com/NGWPC/flows2fim/releases) page and download (double click) `flows2fim-darwin-arm64.tar.gz`
+        - Open the Mac Finder application and navigate to your `Downloads` folder.
+        - Right click > Open the `flows2fim-darwin-arm64.tar.gz` file. This *should* avoid errors arising from Apple security settings.
+        - In a terminal window, move the flows2fim executable to a directory in your `$PATH` (e.g., `/usr/local/bin`), and add execute permissions:
+            ```bash
+            cd ~/Downloads
+            sudo mv flows2fim /usr/local/bin/
+            sudo chmod a+x /usr/local/bin/flows2fim
+            ```
+        - Verify `flows2fim` is executable and in your `$PATH`.
+            ```bash
+            flows2fim --version
+            ```
+        - If the error `"flows2fim" can't be opened because Apple cannot check it for malicious software.` or similar comes up, you may temporarily override your Mac's security settings with the following command:
+            ```bash
+            xattr -d com.apple.quarantine /usr/local/bin/flows2fim
+            ```
+        
+    - **Option 2 - Build from source**
+        - cd into root of repository
+        - Build container
+            - `docker compose up -d`
+        - Get flows2fim CONTAINER_ID
+            - `CONTAINER_ID=$(docker ps -q | head -n 1)`
+        - Issue build script
+            - `docker exec $CONTAINER_ID /bin/bash -c "./scripts/build-darwin-arm64.sh"`
+        - Shutdown container
+            - `docker compose down`
+        - Move executable to `$PATH`
+            - `sudo mv builds/darwin-arm64/flows2fim /usr/local/bin/`
+            - `sudo chmod a+x /usr/local/bin/flows2fim`
+
+3. **`gdal_ls` not supported on MacOS currently (gdal_ls is not included in gdal homebrew installation)**
+
+4. **Verify**
+    - Run `flows2fim --version` to confirm everything works.
diff --git a/README.md b/README.md
index cededf9..1bff499 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # `flows2fim`
 
-[![Build and Test - Linux](https://github.com/ar-siddiqui/flows2fim/actions/workflows/build_and_test_linux.yml/badge.svg?event=push)](https://github.com/ar-siddiqui/flows2fim/actions/workflows/build_and_test_linux.yml)
+[![Build and Test - Linux](https://github.com/NGWPC/flows2fim/actions/workflows/build_and_test_linux.yml/badge.svg?event=push)](https://github.com/NGWPC/flows2fim/actions/workflows/build_and_test_linux.yml) [![Build and Test - Mac](https://github.com/NGWPC/flows2fim/actions/workflows/build_and_test_mac.yml/badge.svg?event=push)](https://github.com/NGWPC/flows2fim/actions/workflows/build_and_test_mac.yml)
 
 ![alt text](image.png)
 ## Overview
@@ -56,7 +56,3 @@ Run `./scripts/build-linux-amd64.sh` This will place the executable in `builds/l
 
 ## Installation
 [Installation](INSTALL.md)
-
-## Examples
-[Examples](EXAMPLES.md)
-
diff --git a/scripts/test_suite_mac.sh b/scripts/test_suite_mac.sh
new file mode 100755
index 0000000..966612d
--- /dev/null
+++ b/scripts/test_suite_mac.sh
@@ -0,0 +1,561 @@
+#!/bin/bash
+
+#       This script provies a comprehensive test suite of the built flows2fim executable on
+#       linux systems, also including regression tests. This script, as well as testdata/reference_data
+#       will need to be manually updated as features change. See testdata/readme.md for more information
+#       on how to update the /testdata directory appropriately.
+
+usage() {
+    echo "
+    This script tests the built flows2fim executable's methods with a combination of parameters.
+    It must be run from the root directory of the flows2fim repository to ensure proper pathing for
+    test data.
+
+    Usage: ./scripts/test_suite_linux.sh [OPTIONS] [METHOD]
+
+    OPTIONS:
+        -d, --dev      Run tests using 'go run main.go' instead of compiled binary
+        -h, --help     Show this help message
+
+    METHODS:
+        controls: Only issue the controls tests.
+            e.g.: ./scripts/test_suite_linux.sh controls
+        fim: Only issue the fim tests.
+            e.g.: ./scripts/test_suite_linux.sh fim
+        validate: Only issue the validate tests.
+            e.g.: ./scripts/test_suite_linux.sh validate
+
+    Providing no method, or 'all', will test all flows2fim methods, controls, fim, & validate.
+    "
+}
+
+# Assign the command line argument if given, else 'all' is the default
+dev_mode=false
+cmd="flows2fim"
+method="all"  # Default to 'all'
+
+# Parse command line arguments
+while [[ $# -gt 0 ]]; do
+    case "$1" in
+        -d|--dev)
+            dev_mode=true
+            cmd="go run main.go"
+            shift
+            ;;
+        -h|--help)
+            usage
+            exit 0
+            ;;
+        -*)
+            echo "Invalid option: $1"
+            usage
+            exit 1
+            ;;
+        *)
+            method="$1"
+            shift
+            ;;
+    esac
+done
+
+# Check if this script is being issued from the repo's root to ensure consistent filepaths
+if [ "$(git rev-parse --show-toplevel)" != "$(pwd)" ]; then
+    printf "Error: This script must be run from the root directory of the flows2fim repository."
+    usage
+    exit 1
+fi
+
+# Ensure flows2fim is installed, available, and executable
+if $cmd --version > /dev/null; then
+    printf "\n\t>>>> Testing availability of flows2fim executable. Output of flows2fim --version: <<<<\n\n"
+    $cmd --version
+else
+    printf "flows2fim is not available"
+    usage
+    exit 1
+fi
+
+# Set paths and configurable variables
+data_folder=testdata
+ref_dir=$data_folder/reference_data
+db_path=$ref_dir/db
+controls_benchmark_dir=$ref_dir/controls
+fim_benchmark_dir=$ref_dir/fim
+flows_files_dir=$ref_dir/flows_files
+library_benchmark=$ref_dir/library
+start_reaches_dir=$ref_dir/start_reaches
+fim_reference_output_formats=$ref_dir/fim_output_formats_mac
+
+test_outputs=$data_folder/test_out
+control_test_outputs=$test_outputs/controls
+fim_test_outputs=$test_outputs/fim
+fim_test_output_formats=$test_outputs/fim_output_formats
+
+# Set counter for failing tests
+total_count=0
+total_passed=0
+
+test_help_statement() {
+    printf "\n\t>>>> Test the --help usage statement <<<<\n\n"
+    $cmd --help
+}
+
+exit_if_failure() {
+    local failed=$1
+    if [ "$failed" -gt 0 ]; then
+        printf "\n\t>>>> ${failed} TESTS FAILED <<<<\n\n"
+        exit 1
+    else
+        exit 0
+    fi
+}
+
+compare_directories() {
+    # Set args
+    local dir1=$1
+    local dir2=$2
+    local fim=$3
+    # Loop through files in dir1 and compare with dir2
+    for file in "$dir1"/*; do
+        filename=$(basename "$file")
+        filepath2="$dir2/$filename"
+        # Skip the one off .vrt relative test when comparing directories
+        if [ "$filename" = "fim_2year_test_rel_false.vrt" ]; then
+            continue
+        fi
+        # Check if the file exists in dir2, and if the "fim" argument was given
+        if [ -f "$filepath2" ] && [ "$fim" = "fim" ]; then
+            tempfile=$(mktemp)
+            if [ "${filename:10:13}" = "vrt" ]; then
+                temp_out=$(diff "$file" "$filepath2")
+                if [ "$temp_out" != "" ]; then
+                    printf "\t Output of diff: \n "$file" "$filepath2" \n $temp_out"
+                    # printf "\t \u274c Files differ: $filename \n"
+                fi
+                continue
+            fi
+            gdalcompare.py $file $filepath2 &> "$tempfile"
+            # cat "$tempfile"
+            gdalcompare_output=$(tail -n 1 "$tempfile" | grep -Eo "[0-9]+" | tail -n 1)
+            # echo "gdalcompare_output: $gdalcompare_output"
+            # Remove temp file
+            rm "$tempfile"
+            # Set tolerance value of gdalcompare
+            gdalcompare_difference_tolerance=2
+            # If there are more than more differences than the tolerance value above, this test fails
+            if (( $gdalcompare_output > $gdalcompare_difference_tolerance )); then
+                printf "\n\t \u274c Files differ: $filename \n"
+            fi
+        elif [ -f "$filepath2" ]; then
+            # Compare the files
+            if ! cmp -s "$file" "$filepath2"; then
+                temp_out=$(cmp "$file" "$filepath2")
+                printf "Output of cmp -s "$file" "$filepath2" : \n\n $temp_out"
+                printf "\t \u274c Files differ: $filename \n"
+            fi
+        else
+            printf "\t \u274c File not found in dir2: $filename \n"
+        fi
+    done
+    # Loop through files in dir2 to find any not in dir1
+    for file in "$dir2"/*; do
+        filename=$(basename "$file")
+        filepath1="$dir1/$filename"
+        # Check if the file does not exist in dir1
+        if [ ! -f "$filepath1" ]; then
+            printf "\t \u274c File in $dir2 not found in $dir1: $filename \n"
+        fi
+    done
+}
+
+# Define functions for each flows2fim method
+controls_test_cases() {
+    local num_test_cases_controls=9
+    local failed_controls_testcases=0
+    total_count=$(( total_count + num_test_cases_controls))
+    # If previous directory exists, remove it
+    if [ -d "$control_test_outputs" ]; then
+        rm -rf "$control_test_outputs"
+    fi
+    # Create new test output directory
+    mkdir -p $control_test_outputs
+
+    printf "\n\t###### ${num_test_cases_controls} TEST CASES FOR flows2fim controls  ######\n\n"
+
+    # Define the recurrence interval array
+    local recurrence_interval=(2 5 10 25 50 100)
+    printf "(1/${num_test_cases_controls})\t>>>> Generate controls.csv files from "
+    printf "${recurrence_interval[*]} year recurrence interval data for Regression Testing. <<<<\n\n"
+
+        for interval in "${recurrence_interval[@]}"; do
+            # Execute flows2fim with each recurrence interval
+            $cmd controls -db $db_path/ripple.gpkg \
+                -f $flows_files_dir/flows_${interval}year.csv \
+                -o $control_test_outputs/controls_${interval}year.csv \
+                -scsv $start_reaches_dir/start_reaches.csv
+        done
+
+    printf "\n(2/${num_test_cases_controls})\t>>>> Regression Tests for all recurrence interval controls files <<<<\n\n"
+        # Compare controls files from recently generated test data and benchmark data
+        # Capture the output of the comparison as a variable if there is no difference
+        diff_output=$(compare_directories "$control_test_outputs" "$controls_benchmark_dir")
+
+        if [ -z "$diff_output" ]; then
+            printf "\t \u2714 No difference in controls files. \n\n"
+        else
+            printf "\t \u274c Outputs differ: \n"
+            printf "\t $diff_output \n"
+            failed_controls_testcases=$((failed_controls_testcases + 1))
+        fi
+
+    ## Assert correct errors thrown
+    printf "(3/${num_test_cases_controls})\t>>>> Assert Error thrown from no start reaches parameter <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        # Test case
+        $cmd controls -db $db_path/ripple.gpkg \
+            -f $flows_files_dir/flows_2year.csv \
+            -o $control_test_outputs/controls_2year.csv &> "$tempfile"
+        # Assign error string
+        expected_error_substring="either a CSV file or start reach IDs and control stages must be provided"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Correct error thrown. \n\n"
+        else
+            printf "\t \u274c Error messaging inconsistent \n\n"
+            failed_controls_testcases=$((failed_controls_testcases + 1))
+        fi
+        # Remove temp file
+        rm "$tempfile"
+
+    printf "(4/${num_test_cases_controls})\t>>>> Assert Error thrown from no start reaches parameter, or output parameter <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        # Test case
+        $cmd controls -db $db_path/ripple.gpkg -f $flows_files_dir/flows_2year.csv &> "$tempfile"
+        # Assign error string
+        expected_error_substring="missing required flags"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Correct error thrown. \n\n"
+        else
+            printf "\t \u274c Error messaging inconsistent \n\n"
+            failed_controls_testcases=$((failed_controls_testcases + 1))
+        fi
+        # Remove temp file
+        rm "$tempfile"
+
+    printf "(5/${num_test_cases_controls})\t>>>> Assert Error thrown from only providing db parameter <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        # Test case
+        $cmd controls -db $db_path/ripple.gpkg &> "$tempfile"
+        # Assign error string
+        expected_error_substring="missing required flags"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Correct error thrown. \n\n"
+        else
+            printf "\t \u274c Error messaging inconsistent. \n\n"
+            failed_controls_testcases=$((failed_controls_testcases + 1))
+        fi
+        # Remove temp file
+        rm "$tempfile"
+
+    ## Test empty controls file created under different flows file and start reaches file inputs
+    printf "(6/${num_test_cases_controls})\t>>>> If start reaches file is empty, confirm controls file is empty <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        # Test case
+        $cmd controls -db $db_path/ripple.gpkg \
+            -f $flows_files_dir/flows_2year.csv \
+            -o $tempfile \
+            -scsv $start_reaches_dir/empty_start_reaches.csv &> /dev/null
+        # Here we use head -n 2 to capture the first two line of the tmp file
+        file_contents=$(head -n 2 "$tempfile")
+        # Remove temp file
+        rm "$tempfile"
+        # Assign error string
+        assert_file_output="reach_id,flow,control_stage"
+        # Compare Error messaging and print
+        if [ "$file_contents" = "$assert_file_output" ]; then
+            printf "\t \u2714 Passed: Output file created and empty. \n\n"
+        else
+            printf "\t \u274c Failed: Output file not empty \n\n"
+            failed_controls_testcases=$((failed_controls_testcases + 1))
+        fi
+
+    printf "(7/${num_test_cases_controls})\t>>>> If flows file is empty, confirm Flow not found error thrown <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        temp_out=$(mktemp)
+        # Test case
+        $cmd controls -db $db_path/ripple.gpkg \
+            -f $flows_files_dir/empty_file.csv \
+            -o $temp_out \
+            -scsv $start_reaches_dir/start_reaches.csv &> "$tempfile"
+        # Assign error string
+        expected_error_substring="Flow not found for reach"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Passed: Flow not found error thrown. \n\n"
+        else
+            printf "\t \u274c Failed: Flow not found error not thrown \n\n"
+            failed_controls_testcases=$((failed_controls_testcases + 1))
+        fi
+        # Remove temp files
+        rm "$temp_out"
+        rm "$tempfile"
+
+    printf "(8/${num_test_cases_controls})\t>>>> If flows file's columns are swapped, confirm Flow not found error thrown <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        temp_out=$(mktemp)
+        # Test case
+        $cmd controls -db $db_path/ripple.gpkg \
+            -f $flows_files_dir/columns_swapped.csv \
+            -o $temp_out \
+            -scsv $start_reaches_dir/start_reaches.csv &> "$tempfile"
+        # Assign error string
+        expected_error_substring="Flow not found for reach"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Passed: Flow not found error thrown. \n\n"
+        else
+            printf "\t \u274c Failed: Flow not found error not thrown \n\n"
+            failed_controls_testcases=$((failed_controls_testcases + 1))
+        fi
+        # Remove temp files
+        rm "$temp_out"
+        rm "$tempfile"
+
+    printf "(9/${num_test_cases_controls})\t>>>> If flows file's values are empty, confirm Flow not found error thrown <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        temp_out=$(mktemp)
+        # Test case
+        $cmd controls -db $db_path/ripple.gpkg \
+            -f $flows_files_dir/empty_flow_values_no_header.csv \
+            -o $temp_out \
+            -scsv $start_reaches_dir/start_reaches.csv &> "$tempfile"
+        # Assign error string
+        expected_error_substring="Flow not found for reach"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Passed: Flow not found error thrown. \n\n"
+        else
+            printf "\t \u274c Failed: Flow not found error not thrown \n\n"
+            failed_controls_testcases=$((failed_controls_testcases + 1))
+        fi
+        # Remove temp files
+        rm "$temp_out"
+        rm "$tempfile"
+
+    controls_passed=$((num_test_cases_controls - failed_controls_testcases))
+    total_passed=$(( total_passed + controls_passed))
+}
+
+fim_test_cases() {
+    local num_test_cases_fim=8
+    local failed_fim_testcases=0
+    total_count=$(( total_count + num_test_cases_fim))
+    # If previous directories exists, remove them
+    if [ -d "$fim_test_outputs" ]; then
+        rm -rf "$fim_test_outputs"
+        rm -rf "$fim_test_output_formats"
+    fi
+    # Create new test output directories
+    mkdir -p $fim_test_outputs
+    mkdir -p $fim_test_output_formats
+
+    printf "\n\t###### ${num_test_cases_fim} TEST CASES FOR flows2fim fim  ######\n\n"
+    printf "\n\t>>>> Test flows2fim fim <<<<\n\n"
+
+    # Define the recurrence interval array
+    local recurrence_interval=(2 5 10 25 50 100)
+    printf "(1/${num_test_cases_fim})\t>>>> Generate fim_year.tif files from "
+    printf "${recurrence_interval[*]} year recurrence interval data for Regression Testing. <<<<\n\n"
+        local fim_file_format="GTiff"
+        for interval in "${recurrence_interval[@]}"; do
+            # Execute $cmd with each recurrence interval
+            $cmd fim \
+                -c $controls_benchmark_dir/controls_${interval}year.csv \
+                -fmt $fim_file_format \
+                -lib $library_benchmark \
+                -type depth \
+                -o $fim_test_outputs/fim_${interval}year.tif &> /dev/null
+        done
+
+    printf "(2/${num_test_cases_fim})\t>>>> Regression Tests for all recurrence interval fim.tif files <<<<\n\n"
+        # Compare fim files from recently generated test data and benchmark data
+        # Capture the output of the compare_directories function as a variable
+        diff_output=$(compare_directories "$fim_test_outputs" "$fim_benchmark_dir" "fim")
+
+        # If there is no differnce, test pass
+        if [ -z "$diff_output" ]; then
+            printf "\t \u2714 No significant difference in fim.tif files. \n\n"
+        else
+            printf "\t \u274c Outputs differ: \n\n"
+            printf "\t $diff_output \n"
+            failed_fim_testcases=$((failed_fim_testcases + 1))
+        fi
+
+    printf "(3/${num_test_cases_fim})\t>>>> Generate fim files in different output formats <<<<\n\n"
+        local file_formats=( "gtiff" "cog" "vrt" )
+
+        for format in "${file_formats[@]}"; do
+            local output_file=fim_2year.$format
+            # Execute flows2fim with each file format (redirecting stdout to tidy logging)
+            $cmd fim \
+                -c $controls_benchmark_dir/controls_2year.csv \
+                -fmt $format \
+                -lib $library_benchmark \
+                -type depth \
+                -o $fim_test_output_formats/$output_file &> /dev/null
+        done
+
+    printf "(4/${num_test_cases_fim})\t>>>> Regression Tests for different output formats <<<<\n\n"
+        # Capture the output of the comparison function as a variable
+        diff_output=$(compare_directories "$fim_reference_output_formats" "$fim_test_output_formats" "fim")
+        # If there is no difference between directories, test pass
+        if [ -z "$diff_output" ]; then
+            printf "\t \u2714 No differences in .cog, .vrt & .tif files. \n\n"
+        else
+            printf "\t \u274c Outputs differ: \n\n"
+            printf "$diff_output \n"
+            failed_fim_testcases=$((failed_fim_testcases + 1))
+        fi
+
+    printf "(5/${num_test_cases_fim})\t>>>> Assert Error thrown from no controls file parameter <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        # Test case
+        $cmd fim \
+                -fmt $format \
+                -lib $library_benchmark \
+                -type depth \
+                -o $fim_test_outputs/fim_test.tif &> "$tempfile"
+        # Assign error string
+        expected_error_substring="missing required flags"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Correct error thrown. \n\n"
+        else
+            printf "\t \u274c Error messaging inconsistent \n\n"
+            failed_fim_testcases=$((failed_fim_testcases + 1))
+        fi
+        # Remove temp file
+        rm "$tempfile"
+
+    printf "(6/${num_test_cases_fim})\t>>>> Assert Error thrown from no library parameter <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        # Test case
+        $cmd fim \
+                -c $controls_benchmark_dir/controls_2year.csv \
+                -fmt "GTiff" \
+                -type depth \
+                -o $fim_test_outputs/fim_test.tif &> "$tempfile"
+        # Assign error string
+        expected_error_substring="missing required flags"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Correct error thrown. \n\n"
+        else
+            printf "\t \u274c Error messaging inconsistent \n\n"
+            failed_fim_testcases=$((failed_fim_testcases + 1))
+        fi
+        # Remove temp file
+        rm "$tempfile"
+
+    printf "(7/${num_test_cases_fim})\t>>>> Assert Error thrown from no output file parameter <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        # Test case
+        $cmd fim \
+                -c $controls_benchmark_dir/controls_2year.csv \
+                -fmt $format \
+                -type depth \
+                -lib $library_benchmark &> "$tempfile"
+        # Assign error string
+        expected_error_substring="missing required flags"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Correct error thrown. \n\n"
+        else
+            printf "\t \u274c Error messaging inconsistent \n\n"
+            failed_fim_testcases=$((failed_fim_testcases + 1))
+        fi
+
+    printf "(8/${num_test_cases_fim})\t>>>> Assert Error thrown from empty controls file <<<<\n\n"
+        # Create and assign temp file
+        tempfile=$(mktemp)
+        # Test case
+        $cmd fim \
+                -c $flows_files_dir/empty_file.csv \
+                -fmt $format \
+                -lib $library_benchmark \
+                -type depth \
+                -o $fim_test_outputs/fim_test.tif &> "$tempfile"
+        # Assign error string
+        expected_error_substring="no records in control file"
+        # Search (grep) for expected error substring in temporary output file
+        if grep -q "$expected_error_substring" "$tempfile"; then
+            printf "\t \u2714 Correct error thrown. \n\n"
+        else
+            printf "\t \u274c Error messaging inconsistent \n\n"
+            failed_fim_testcases=$((failed_fim_testcases + 1))
+        fi
+        # Remove temp file
+        rm "$tempfile"
+
+    #printf "(9/${num_test_cases_fim})\t>>>> Test flows2fim fim pull from S3 <<<<\n\n"
+
+    fim_passed=$((num_test_cases_fim - failed_fim_testcases))
+    total_passed=$(( total_passed + fim_passed))
+
+}
+
+validate_test_cases() {
+    local num_test_cases_validate=0
+    local failed_validate_testcases=0
+    total_count=$(( total_count + num_test_cases_validate))
+
+    printf "\n\t###### ${num_test_cases_validate} TEST CASES FOR flows2fim validate  ######\n\n"
+    # printf "( 1/${num_test_cases_validate})\t>>>> Test validate <<<<\n\n"
+    # flows2fim validate
+
+
+    validate_passed=$((num_test_cases_validate - failed_validate_testcases))
+    total_passed=$((total_passed + validate_passed))
+}
+
+# Control flow for methods and test cases
+if [ "$method" = "all" ]; then
+    printf "\n\t>>>> TESTING ALL METHODS (controls, fim, & validate) <<<<\n"
+    test_help_statement
+    controls_test_cases
+    fim_test_cases
+    validate_test_cases
+    printf "\n\t>>>> (${total_passed}/${total_count}) TESTS PASSED <<<<\n\n"
+    total_failed=$((total_count - total_passed))
+    exit_if_failure $total_failed
+elif [ "$method" = "controls" ]; then
+    controls_test_cases
+    printf "\n\t>>>> (${total_passed}/${total_count}) TESTS PASSED <<<<\n\n"
+    total_failed=$((total_count - total_passed))
+    exit_if_failure $total_failed
+elif [ "$method" = "fim" ]; then
+    fim_test_cases
+    printf "\n\t>>>> (${total_passed}/${total_count}) TESTS PASSED <<<<\n\n"
+    total_failed=$((total_count - total_passed))
+    exit_if_failure $total_failed
+elif [ "$method" = "validate" ]; then
+    validate_test_cases
+    printf "\n\t>>>> (${total_passed}/${total_count}) TESTS PASSED <<<<\n\n"
+    total_failed=$((total_count - total_passed))
+    exit_if_failure $total_failed
+else
+    printf "\n\t>>>> NO TEST CASES WERE RUN <<<<\n\n"
+    usage
+fi
\ No newline at end of file
diff --git a/testdata/reference_data/fim_output_formats_mac/fim_2year.cog b/testdata/reference_data/fim_output_formats_mac/fim_2year.cog
new file mode 100644
index 0000000..d47f776
Binary files /dev/null and b/testdata/reference_data/fim_output_formats_mac/fim_2year.cog differ
diff --git a/testdata/reference_data/fim_output_formats_mac/fim_2year.gtiff b/testdata/reference_data/fim_output_formats_mac/fim_2year.gtiff
new file mode 100644
index 0000000..9241c5a
Binary files /dev/null and b/testdata/reference_data/fim_output_formats_mac/fim_2year.gtiff differ
diff --git a/testdata/reference_data/fim_output_formats_mac/fim_2year.vrt b/testdata/reference_data/fim_output_formats_mac/fim_2year.vrt
new file mode 100644
index 0000000..8aad911
--- /dev/null
+++ b/testdata/reference_data/fim_output_formats_mac/fim_2year.vrt
@@ -0,0 +1,16 @@
+<VRTDataset rasterXSize="1185" rasterYSize="1163">
+  <SRS dataAxisToSRSAxisMapping="1,2">PROJCS["NAD83 / Conus Albers",GEOGCS["NAD83",DATUM["North_American_Datum_1983",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6269"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4269"]],PROJECTION["Albers_Conic_Equal_Area"],PARAMETER["latitude_of_center",23],PARAMETER["longitude_of_center",-96],PARAMETER["standard_parallel_1",29.5],PARAMETER["standard_parallel_2",45.5],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","5070"]]</SRS>
+  <GeoTransform> -1.9071349570219149e+06,  3.0000000000000000e+00,  0.0000000000000000e+00,  3.0706380139037063e+06,  0.0000000000000000e+00, -3.0000000000000000e+00</GeoTransform>
+  <VRTRasterBand dataType="Float32" band="1">
+    <NoDataValue>-9999</NoDataValue>
+    <ColorInterp>Gray</ColorInterp>
+    <ComplexSource>
+      <SourceFilename relativeToVRT="0">/Users/runner/work/flows2fim/flows2fim/testdata/reference_data/library/24274741/z_nd/f_17668.tif</SourceFilename>
+      <SourceBand>1</SourceBand>
+      <SourceProperties RasterXSize="1185" RasterYSize="1163" DataType="Float32" BlockXSize="1185" BlockYSize="512" />
+      <SrcRect xOff="0" yOff="0" xSize="1185" ySize="1163" />
+      <DstRect xOff="0" yOff="0" xSize="1185" ySize="1163" />
+      <NODATA>-9999</NODATA>
+    </ComplexSource>
+  </VRTRasterBand>
+</VRTDataset>