The Seasonal Fee Rates Experiment
At Yosemite, one of the most heavily visited units of the National Park System, the campgrounds are chronically crowded with waiting lines during the peak summer season. For a brief time in the mid-1970s, the park reduced the fee at certain campgrounds from $4 to $2 during the months of November through March, the object being to shift some of the summer use to the off-season.
No such shift occurred, suggesting that few if any of the summer campers were so hard-pressed by the $4 fee as to find the winter discount an incentive to change their vacation plans. Because per capita operating costs were higher in the winter, the reduced seasonal rate was discontinued. The experiment was not repeated elsewhere. 
In 1976 the Bureau of Outdoor Recreation (BOR) commissioned Economic Research Associates to conduct a study of the public's willingness to pay user charges for recreation facilities. "Increased emphasis has...been placed by the Office of Management and Budget on developing more definitive economic criteria for allocation of resources, as well as encouraging greater self-sufficiency of recreation areas and facilities/services through the application of user fees," the study report noted in justifying its purpose.
The contracted firm surveyed 800 households representing varying ages, incomes, educational levels, and geographic areas. Its report revealed that a majority of all demographic groups favored the user fee concept as opposed to total reliance on general tax revenues, and that most people were willing to pay higher fees than were then in effect. Interestingly, opposition to user fees on the grounds that they deterred lower-income participation came more from higher income and education levels; those of lower income and education, who did patronize recreation facilities less, expressed the greatest support for fees. BOR distributed the report to Federal, state, and local recreation-providing agencies to encourage them to place greater reliance on user fees as a way out of their current funding difficulties. 
1Memorandum, Acting Director Daniel J. Tobin, Jr., to Director, Heritage Conservation and Recreation Service, Feb. 24, 1978, NPS Ranger Activities and Protection Division, Washington, D.C. (hereinafter cited as WASO-535).