No problem, you’ve got your GPS. Right? How could anyone possibly get lost when they have their GPS? GPS is a useful tool for getting to the trailhead, getting from the trailhead to the canyon entrance and from the top of the canyon exit back to the trailhead, but it is not a replacement for good map reading skills. GPS is unreliable inside the canyon. It may also prove inadequate as you attempt to work your way around the maze of side drainage on your way to or back from the canyon. They’re great for traveling in a straight line from point A to point B, but a good topographic map and the skills to use it will never fail you. And maps don’t require batteries.

Perhaps you feel you don’t need a map because you are carrying the pages from your trusty guidebook or the sheets you printed off the internet. What happens when you misinterpret a line or two in the directions. You go just a little too far or not quite far enough when you attempt to enter or exit. You’re not where you think you are and now can’t make sense of the next lines in the directions. Can you correct your course without a map? Or what if you discover you can’t travel with your group as fast as the author did? It’s getting late. It will be dark soon. You need to find an exit out of the canyon now. Can you find one without a map?

I posted a new 15-page section to the subscriber index. It includes information about canyon topos, route planning, understanding contour lines on a topographic map, macro and micro navigation, orienting a map, and more.

There are a number of factors that contribute to the potential for a flash flood. The most obvious factor is the weather, but it is not the only one. You must also consider watershed and potential runoff.

The surface flow of all precipitation is called runoff. The amount of runoff in an area depends on several variables including the amount of precipitation, size of the watershed, surface slope, permeability of surface materials, density of vegetation cover and evaporation rate.