Idaho Statutes are clear on the issue of who is liable for costs incurred for search and rescue efforts. If the person who is lost has intentionally ignored signs, or has wandered into an area that is posted off limits, such as an out of bounds ski area, that person (18 years or older) is liable for the costs incurred for the search and rescue effort.

http://www3.state.id.us/oasis/2003/H0116.html

There is nothing in Idaho Statutes that even remotely suggests that a lost pilot would be expected to reimburse the state for search and rescue costs. We pay a $12 fee each year into a fund for such efforts.