I can’t tell you how many times I have gotten to the bottom of a hill only to realize I took a wrong turn and have to climb right back up it. I recently spent the better part of two days figuring out how to put topo maps on my garmin. In an effort to save you that same hassel, I wrote out step-by-step instructions on how to get free maps for your GPS.
Install Garmin Basecamp
Go to http://www.garmin.com/en-US/shop/downloads/basecamp to select and download the the appropriate version for your computer (Windows or Mac).
Install 7-Zip File Manager
Go to http://www.7-zip.org/ to select and download the the appropriate version for your computer (32 or 64-bit).
Head to www.gpsfiledepot.com to select and download free maps for your GPS. There are tons to choose from. If you are looking for routable topo maps of the USA, then I will save you some time. Here are the links to each individual region. They are all separate maps, but can be enabled on the garmin at the same time. Alaska, Hawaii, Midwest, Mountain, Northeast, Pacific, South Atlantic, South Central
Unzip Map Files
Locate the downloaded file and right click on it.
Select “Open With” -> “7-Zip” -> “Extract Here.”
The result will be a folder titled something like “US_Hawaii_OSM_Topo_v25a”, depending on which map you are working with.
Once you have done this for each individual map, then move on to the next step.
Install maps on Garmin Basecamp
Open each map folder individually and double click the file that looks like “install_US_Midwest_OSM_Topo” This will automatically install map on Basecamp.
Install maps on Garmin
In Garmin Basecamp: Click Maps -> install maps.
Select all areas you want to install on your garmin. Use the dropdown menu at the bottom because you can install multiple areas at once.
The maps are now installed on your garmin. Be sure to go into your map settings and enable the maps you wish to see.
If you have input or questions, then feel free to comment or contact me directly.