Operating a GPS for backcountry or geocaching use is quite simple after a few minutes of experimenting with a device and following some simple GPS instructions like those included in this article. This is one of a series of articles we have on our site about GPS usage; see below for a complete listing of our GPS how-to articles.

This article discusses how to find your location on a print map using coordinates of your current location recorded by a gps. We often use a basic Garmin eTrex unit as our go-to example, but all GPS units function in very similar ways and have similar features. Before you start with these instructions, learn which keys, buttons or menu selections activate the following basic functions on the GPS you're using:

 • Move between pages or menu screen - Usually a button labeled "Page". Like choosing between open programs or tabs on your computer screen.

 • Scroll within choices on a page - this may be a "rocker" button or two "up-and-down" buttons, similar to the function a mouse or cursor movers does on a computer.

 • Select a choice - usually a button that says "Enter". Serves the same function as the enter key on a computer or "OK" on a smartphone.


First, you need to make sure the coordinate units on your GPS (latitude/longitude, UTM, etc) are set to the same format as appearing out to the side of your map. If you're not sure how to do this, read this article on how to change measurement units and map format setting on a gps.

Then, write down the GPS address for your current location. Either mark your location to capture the address, or some will show your current location on a navigation page. See our article on how to mark a waypoint with a GPS for more information.

The map will have reference coordinates marked at periodic intervals - every minute for example, or every kilometer on the UTM grid. Armed with one half of the coordinate pair from the GPS, find the closest reference points on the map, and estimate the distance you are between the tic marks. For example, assume the longitude tic marks are shown for 111 degrees, 25 minutes and 111 degrees, 26 minutes, etc. If the GPS shows you at 111 degrees, 25.345 minutes longitude then you know you are approximately 1/3 of the way between the 2 map tic marks. Draw a vertical line down from that estimated point. Then do the same process for the latitude coordinates: assume the latitude tic marks are shown for 33 degrees, 43 minutes and 33 degrees, 44 minutes, etc. If the GPS shows you at 33 degrees, 43.769 minutes latitude then you know you are approximately 3/4 of the way between the 2 map tic marks. Draw a horizontal line across from that estimated point.

Where the 2 lines you've drawn intersect is your approximate location on the print map. To narrow it down further, and to confirm your calculations, look around and compare notable landmarks you see to those appearing on the printed topo map.

We have a nice library of how-to articles on this site. If you rent a GPS from LowerGear, we will also include a print or online user guide with full details on how to use it. We are also available to assist you over the phone. Links to our other articles in this series follow:

Our GPS Overview page
How to Mark a Waypoint with a GPS
How to Manually Enter a Waypoint Coordinate into a GPS
How to Navigate to a Waypoint with a GPS
How and Why to Change Map Orientation on a GPS
How to Change Measurement Units and Map Format Setting on a GPS
How to Record a Track of Waypoints on a GPS
What does WAAS Mean for a GPS
Using a GPS for Geocaching

See all of the GPS navigation and geocaching rental gear we can deliver to you for your next back-country, geocaching or driving adventure!

We'll ship your rented GPS unit direct to your home before your trip, or to any other convenient location. Or, you can pick up the GPS at our backpacking and camping retail store in the Phoenix area if your travels are nearby. After your trip, just package up the rented GPS back into the same box we shipped to you, use the prepaid return label, and drop off the rental gear at the most convenient shipping point used by our carrier - there will be many options in every city in the US.

If we're shipping rental gear to you, order far enough in advance to allow for a few days of transit time. Note that you are not charged rent during these transit days. We can get GPS rentals to you in anywhere in the US in 5 business days or less via UPS Ground, and expedited shipping methods for quicker deliveries are available. For more information, call us at (480) 348-8917 or stop by our outdoor retail store in Tempe, Arizona.