The most basic risk of hiking is getting lost. And just as it’s possible to drown in your kitchen sink, it’s possible to get dangerously lost in just about any outdoor locale beyond your back yard.
It doesn’t really matter what kind of map you have, so long as it tells you where to turn to get back where you came from. There are topographic maps and Google maps and specially created trail maps of the kind crafted by Tom Harrison, one of our sponsors. All are better than nothing.
The map can be in your head, but the only way it gets there is by repeated exposure to the same trails. Never take a strange trail without map. Really, never. And keep in mind: weather can change the trail you think you have memorized: if 600-year-old, 250-foot-long redwood has fallen across the trail in front of you, your memory of how to get to where you need to be might not be of much help because your access will be blocked for a long distance in two directions, and if the tree’s fat enough, you won’t be able to climb over it. So even if you think you know the place by heart, take a map anyway.
Also: Keep your map dry — seal it in a Ziploc — sweat is more likely to ruin it than rain.