Walking the Dog

Suburban Walks > Hiking with a GPS

Hiking with a GPS

What is a GPS? GPS stands for global positioning system. Civilians can buy a GPS unit that will give them their position anywhere on the earth to within 30 feet, often within 10 feet. One can purchase a GPS for as little as $80 and for over $500. A GPS for hiking is easy to carry in the hand, so you can use it to help you navigate to any location for which you know the latitude and longitude. You can get lat-long coordinates from Google Earth that can be downloaded from Google Earth.

I have what Garmin refers to as an "On The Trail Mapping GPS". I can record one of my hikes and then upload the hike track and waypoints to the computer for use with mapping software. A GPS track is like a breadcrumb trail with a location taken several times a minute as you hike. A waypoint is a named location that you enter while hiking in case you want to return to that point or mark it (later) on a map. National Geographic sells topographic maps of the United States that you can use by uploading your hiking data and plotting it automatically on a topographic map. Garmin sells mapping software that includes all of the streets in the United States. You can see where you hiked relative to local roads.

When I go on a hike in a place like Davis Farm Conservation Land in North Sudbury, I turn on my GPS at the start of the hike and turn it off at the end of the hike. When I arrive home, I upload my hike to Garmin mapping software, save it in gpx format, and load it onto Google Earth Plus. A subscription to Google Earth Plus is $20 annually and it allows you to upload data to Google Earth. I have uploaded 6 hikes of Davis Farm. I can display each hike in a different color. I have set waypoints to help me find trail junctions when the trees and shrubs leaf out in the Spring and obscure the trails. On Google Earth, I can see where Davis Farm trails are relative to the nearby National Wildlife Refuge, relative to homes, and relative to wetlands. It's nice to know where the wetlands are so that you don't try to hike through them.

On longer hikes taken with my dog, Lady Juliet, I like to know where the water is so she can get a drink when it's hot. I also like to know how far I am from the trailhead so I can know when to turn around. My GPS has a sunrise/sunset feature that lets me know when it will get dark. This helps me to avoid becoming a doddering old fool who has to be rescued by the police.

One last thing I do with my GPS is to plan my route to new conservation land. For example, Weston and Carlisle have conservation maps showing hiking trails. These may be purchased at the respective town halls. Concord and Sudbury have similar maps online. With a street map loaded on the GPS, I can drive directly to any trailhead of interest. I also have a good idea of where I will walk and how to plan a loop route. For a large conservation area, I can also enter waypoints before I start a hike. I can leave the map at home and just carry the small GPS. Lady Juliet does not have to sit and wait on a hike while I examine a map to try and figure out where I am.

So, when I start on a hike, I make certain that I have: Lady Juliet, the GPS, my cellphone, and a pocket full of dog treats.