Demand curves were estimated for waterfowl hunting and nonconsumptive recreational use from use rate and variable expenditure data collected at the Bear River Migratory Bird Refuge and the Farmington Bay Waterfowl Management Area during fiscal 1969. Consumer's surplus and monopoly revenue estimates were then derived from the demand functions. Adjusted estimates of consumer's surplus for waterfowl hunting amounted to $7,260 per year at Bear River and $11,400 per year at Farmington Bay. For nonconsumptive recreation annual consumer's surplus was estimated to be $18,700 at Bear River and $3,760 at Farmington Bay. Monopoly revenue estimates were between one-half and one-fourth the corresponding consumer's surplus estimates. The capitalized value (at 8 percent interest) of predicted annual consumer's surplus for all recreation was $865,800 for Bear River and $299,000 for Farmington Boy. Capitalization of the corresponding monopoly revenue estimates gave $276,900 for Bear River and $92,100 for Farmington Bay. At 3 percent interest, the capitalized consumer's surplus values increase to $4,242,000 for Bear River and $1,184,000 for Farmington Buy, while those for monopoly revenue increase to $1,330,000 for Bear River and $350,000 for Farmington Bay. The author believes that consumer's surplus estimates are more valuable than monopoly revenue estimates for comparison with other values included in the benefit/cost analysis of water development projects because the needed values include more than a non-discriminating monopolist can extract. It will never be possible to make additive estimates of all of the relevant values of natural areas used for outdoor recreation. Allocation decisions must draw on several disciplines in addition to economics to determine where the balance will swing for the greatest net benefit to society, nevertheless, the author believes that exceptions exist where the native flora and fauna can be managed to attract visitors such than an area can remain in natural production in perpetuity and be competitive with potentially conflicting interests in terms of measurable economic values. It is believed that future research should concentrate on high-value sites and be directed toward sensitivity analysis, the simultaneous evaluation of alternative uses, the influence of the travel-time variable, marginal resource values, and off-site benefits.