These days, you have to be alert everywhere. Just a few years back, a client of mine had me find and remove some traps aimed at injuring horses and riders, along a reasonably popular bridle path. The worst was a steel cable strung across the trail that could have, under the right circumstance, killed a rider.
As well, any time I'm on and off the trails, I'm wary of trouble as they've been finding evidence of meth labs all over the area. In other regions, covert pot farms have been found with some degree of deterrents or defenses (including traps and even armed guards).
"The urge to save humanity is almost always a false front for the urge to rule."