Numbers of nesting raptors on a 31.1-km2 area in western Wyoming declined 30% between 1947 and 1975. The common raven (Corvus corax) population increased from 3 to 11 pairs, and Swainson's (Buteo swainsoni) and red-tailed hawks (B. jamaicensis) combined decreased from 17 to 9 pairs. Data from 1948, 1978, and 1979 support these changes. Nesting success was 50% less in 1975 than in 1947, and nesting dates for most species were later in 1975. Increases in human disturbance and changes in the natural environment are described and indicated as factors effecting the raptor population decline. J. WILDL. MANAGE. 45(4):865-872 Comprehensive monitoring of raptor populations is critically important to raptor management and conservation efforts. Breeding surveys (Luttich et al. 1971, Gates 1972, Johnson 1973, McInvaille and Keith 1974, Murphy et al. 1975), migration counts (Spofford 1969, Hackman and Henny 1971), and banding and productivity data (Henny 1972) all have application in population monitoring. Intensive breeding surveys combined with productivity data have the advantage of providing detailed information that can be gathered periodically on known populations. The value of resurveying previously censused raptor populations, to determine their status over time, has been demonstrated by Henny et al. (1973) and Belyea (1976). Nesting studies including all raptor species in an area are infrequently done, yet they are important in understanding the ecology of population changes. In this paper we compare results of intensive nesting surveys conducted in 1947 (Craighead and Craighead 1950, 1956) and 1975, along with observations and data from other years, to reveal changes that have occurred in the collective raptor population. We acknowledge financial support from the New York Zoological Society; the Atmospheric Sciences Research Center, State University of New York at Albany; and the Environmental Research Institute. Appreciation is extended to S. Walton, F. L. Craighead, C. Craighead, P. Seligman, J. Kirkley, J. Shuler, and M. Demment for field assistance. J. J. Hickey and C. E. Braun offered helpful criticism of the manuscript.