Pg. G2 (fig. 1), G4 (table 1), G6 (fig. 2), G10-11 (table 2), G51-53, pl. 1. Ice Harbor Member of Saddle Mountains Basalt of Yakima basalt subgroup [informal] of Columbia River Basalt Group. Previously called flows at Ice Harbor Dam by Wright and others (1973, GSA Bull., v. 84, p. 371-386). At type locality, consists of two thick flows, separated by a deposit of tephra associated with several thin, discontinuous flows, above the Elephant Mountain Member of Saddle Mountains Basalt. Is considered older than the Lower Monumental Member (new), youngest member of the Saddle Mountains. Thickness 15 to 30 m. Divided into 3 informal units (ascending): basalt of Basin City (present north of Ice Harbor area), basalt of Martindale, and basalt of Goose Island. Age is late Miocene (8.5 Ma, citing McKee and others, 1977, GSA Abs. with Prog., v. 9, no. 4, p. 463-464). (Ice Harbor Member adopted by the USGS.)
Type locality (see fig. 1, loc. 59 and pl. 1, fig. P): abandoned quarry on south side of Snake River, 2.6 km west of Ice Harbor Dam, in SE/4 SE/4 sec. 22, T. 9 N., R. 31 E., Humorist quadrangle, Walla Walla Co., southeast WA.
[Yakima basalt subgroup considered informal and should not be capitalized. "Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Columbia River Basalt Group adopted by the ID, OR, and WA Geol. Surveys, and the USGS.]

Source: Publication; US geologic names lexicon (USGS Bull. 1564, p. 80); GNU records (USGS DDS-6; Menlo GNULEX); Changes in stratigraphic nomenclature, 1979 (USGS Bull. 1502-A, p. A35).