The data set used in this paper was

The data set used in this paper was col- lected at MCFR headquarters by the re- serve management, which offered those who gave their names and addresses the opportunity to win wildlife photographs. A total of 755 of approximately 3000 dom- estic visitors entered the drawing in 1988. The sample shows a similar distribution, with respect to sites of origin, as a smaller data set collected independently over 3 months during the summer of 1988. We consequently assume the sample is repre- sentative of the true domestic visitor pop- ulation