1. Desolation Wilderness: data from 1997-1998 visitor response to fees, fee demonstration project
- Author(s):
 - Watson, Alan E.; Puttkammer, Annette; Christensen, Neal A.
 
2. Boundary Waters Canoe Area Wilderness: 2007 visitor survey data
- Author(s):
 - Dvorak, Robert G.; Watson, Alan E.; Christensen, Neal A.; Borrie, William T.; Schwaller, Ann
 
	U.S. Department of Agriculture