Found a trick for reading contour lines that cut my route planning time in half

I used to spend ages staring at topo maps trying to figure out if a trail was gonna kick my butt or not. About two weeks ago I tried counting the contour lines between two points on a map for a trip in the Smokies. Turns out if you divide that number by 2 you get a rough idea of the elevation gain in hundreds of feet. It's not perfect but it saved me from planning a route with a 2,000 foot climb I wasn't ready for. Has anyone else stumbled onto a map reading shortcut that just clicked for you?

2 comments

2 Comments

wendy_jackson1mo ago

Hang on though, those contour intervals can vary a lot between different maps. I was looking at a USGS quad for a section of the Appalachian Trail in Virginia and the interval was 40 feet, not the standard 20. My buddy used that same trick and ended up underestimating a climb by like 800 feet because he didn't check the map legend first. Also some trails just weave back and forth across the same slope, so counting lines gives you the total vertical but doesn't tell you about the ups and downs along the way. I'd still double check with a profile tool or something if the route looks borderline.

abby_wilson511mo ago

Yep @wendy_jackson, totally. It's like that thing where people assume all gas station hot dogs are the same price but some charge double. I learned that lesson the hard way mapping trails in Colorado, had a map with 50 foot intervals instead of 40. Missed a whole ridge because I didn't check.