When Joyce Farbe saw how many cars were parked at the Iron Creek Trailhead when she pulled in, she knew it would be a busy day. It was a warm, late summer morning, and her destination – Sawtooth Lake – is one of the most popular day hikes in Central Idaho. Cars were spilling out of the parking lot and lined the dirt road for a quarter mile. Farbe tightened her boot laces and pulled her backpack onto her shoulders. Before she could get going, her work began: She approached two men as they printed their name on a wilderness permit at the trailhead.