[Herbert C. Kraft et al. (1994)] An unknown proportion of the site consists of a large area of oyster shell up to 120 cm (4 ft) deep in its southern end. Radiocarbon dates indicate that the shell accumulated 6000 to 4400 and 2500 to 2200 years ago, but projectile points indicate utilization of the place 7000 to 2500 years ago and again from 1500 to 500 years ago. The site has been excavated in three separate projects . In 1963, Louis Brennan excavated at Dogan Knoll, the eastern edge of the bluff top, and from 1968 to 1972, he worked in the heart of the shell deposit removing Figure 1. Dogan Point site map. 26 Spring 1994 No. 107 Geological Information Middle to Late Holocene age capped by a smaller oyster stratum in humic anthrosols, all covered with contemporary humic earthworm-worked soils (Schuldenrein 1994). Montrose Point, the larger landform of which Dogan Point is a part, was probably once a cliffed headland, with spit and quieter estuarine area at the base of the point (Figure 2). Based on the submarine topography, the shoreline was 45 m (148 ft) west of the site at 2500 years ago, 200 m (656 ft) west at 5500 B.P., and 500 m (1640 ft) west at 7000 B.P. (Figure 3). 8500 to 5500 years ago, during the Hypsithermal, sedimentation prevailed over sea-level rise. The drier condition would have favored the dominance of the marine environment over the riverine one, while the opposite has been true since the hemlock decline, or the end of the Hypsithermal.