- Derek B. Booth
- Timothy J. Walsh
- Kathy Goetz Troost
- Scott A. Shimel
- Booth, D.B., Walsh, T.J., Goetz Troost, K., and Shimel, S.A., 2012, Geologic map of the east half of the Bellevue South 7.5’ x 15’ quadrangle, Issaquah area, King County, Washington: U.S. Geological Survey Scientific Investigations Map 3211, scale 1:24,000. (Available at https://pubs.usgs.gov/sim/3211/.)
- The Issaquah area includes several of the most outstanding geologic features of the eastern Puget Lowland region. Folds have warped thousands of meters of Tertiary sedimentary and volcanic rocks. Several hundred meters of both glacial and postglacial sediment have accumulated in a deep glacial trough, which is now partly occupied by Lake Sammamish but which was previously the conduit for massive volumes of meltwater during ice-sheet occupation and retreat. The eastern projection of an east-west-oriented crustal structure, which reflects Tertiary through Holocene fault displacement, extends across the eastern part of the map area.
- Lummi Indians - June 9th [of 1853]. Accompanied by Goliah, I visited the mouth of the Lummi, where the headquarters of the Lummi band is supposed to be. We had our little canoe, and, the wind rising, we became quite wet, so that we decided to get out and walk. At the first mouth I found a settler named Hedge. He was living in a house of mats, like the Indians. He had an Indian wife with him and a white wife in the States. He had a great deal to tell me, most of which I do not believe. He boasts of his claim and praises the richness of the valley, which, however, he has not explored. He claims to have a great control over the Indians, and tells me that Chowitzan, chief of the Lummis, having heard of my coming and fearing that I might be after him, had gone to Victoria.21
- Renton Formation—Nonmarine fine- to medium-grained arkosic sandstone and siltstone containing abundant subbituminous coal beds and carbonaceous shale.
- Tukwila Formation—Andesitic to dacitic volcanic sandstone, siltstone, shale, tuff-breccia, tuff, volcanic mudflow (lahar), carbonaceous shales, and minor lava flows or sills. Typically massive; only local sedimentary interbeds indicate structure. K-Ar age on plagioclase from tuff-breccia at top of unit, about 3 km west of quadrangle, yielded an age of 42.0±2.4 Ma (Turner and others, 1983)