The Cuyamaca Mountains of interior San Diego County are a remote region characterized by a vast diversity of natural and cultural resources. Located 60 km. east of San Diego, and within the ethnographic homeland of the Kumeyaay Indians, the Cuyamacas comprise a major portion of the Peninsular Range. The region is drained by the San Diego and Sweetwater rivers, and ranges in elevation from 1,000 to 2,000 m. above sea level. Local plant communities include well-developed chaparral, grassland meadow, and oak-pine woodland associations.

Like their native American counterparts, Euro-American petroglyphs occur throughout Cuyamaca Rancho State Park. Most of them appear to be recent, being of the "Kilroy Was Here" variety. One, however, appears to be historically significant, and has been recorded as site SDI-9086H. The Lookout site, SDI-9086H, is located atop Cuyamaca Peak. It is the location of the Cuyamaca Lookout Tower, now out of service. From the site, one is afforded a commanding view of the surrounding countryside, much of which is included within the Cleveland National Forest. Pecked into a granite boulder adjacent to the tower is a petroglyph in the shape of the United States Forest Service emblem, complete with the names of all the lookout's smoke watchers between the years 1917 and 1932. Probably produced sometime shortly after 1932, this petroglyph serves to document the humanistic nature of rock art. Like his Kumeyaay counterparts, a Forest Service employee found here the inspiration and necessity to record on rock the presence of his people and, like the Kumeyaay, that presence has been outlived by the petroglyph.

The recent DPR investigations have been directed toward a better understanding of the Annadel prehistoric archaeological record. One goal of this work has been to delineate the boundaries of the park's primary obsidian source (i.e., the "Annadel" source). Special attention has also been given to x-ray fluorescence spectrography and obsidian hydration studies. These studies have helped to better illustrate the chemical variability of the local obsidian, and to better define the local chronological sequence (Origer 1982; Origer and Wickstrom 1982). Perhaps the most interesting survey finding has been the tentative identification of a previously undetected obsidian source occurring within and adjacent to the park. This paper is a brief discussion of these recent findings.