This paper develops a theory of interdependent utility functions in examining congestion in recreation demand equilibria. The notion is examined empirically through the development of congestion forecasting functions which individuals use to sort themselves among a set of recreation sites. These forecasts are used in site choice models estimated on revealed preference information. An interesting outcome of this exercise is that recreation site attribute changes, which are projected to provide positive utility, may in fact generate negative utility if the effect of the change on congestion is jointly considered.