By A. H. KOSCHMANN and M. H. BERGENDAHL - USGS 1968
Mineralized areas in Whatcom County are in the Cascade Range, and the ore deposits are related to the intrusions of granodiorite along the axis of the range.
Most of the gold mined in Whatcom County came from the Mount Baker and Slate Creek districts, which produced about equal amounts. From 1903 through 1953, the county produced 89,156 ounces of lode gold and 2,425 ounces of placer gold, about half of which was mined in the late 1930's. No production was recorded from 1953 to 1959.
MOUNT BAKER DISTRICT
The Mount Baker district is in north-central Whatcom County between lat 48°50' and 49°00' N. and long 122°25' and 122°35' W.
Early discoveries of placer gold along Ruby Creek focused attention on this district, but no important deposits were found there until 1897 (Patty, 1921, p. 21). The most important lode gold mines were the Boundary Red Mountain and the Lone Jack. District production of lode gold through 1948 was estimated at a minimum of 55,000 ounces; no production was reported from 1948 through 1959. Huntting (1955, p. 132, 133) reported some placers in the district, but production from them was probably negligible.
The country rock in the district is slate (Lyon, in Landes and others, 1902, p. 42). The ore deposits are in quartz veins or in sulfide-rich veins of calcareous material. Gold is present as native gold, as a telluride, and in association with sulfides.
SLATE CREEK DISTRICT
The Slate Creek district is in the extreme eastern part of Whatcom County, in the heart of the Cascade Range, within lat 48°45' and 48°50' N. and long 120°45' and 121°00' W.
Gold discoveries were made as early as 1893 at the Gold Ridge, Eureka, and Mammoth properties (Lyon, in Landes and others, 1902, p. 48), but production data were not found for the years before 1933. Total production from 1933 through 1953 was 29,172 ounces; no production was reported from 1953 through 1959.
The country rock consists of shale, limestone, and sandstone of the Similkameen Formation of Cretaceous age (Lyon, in Landes and others, 1902, p. 46, 47). These sediments are compressed into steep north-trending folds. Numerous vertical dikes of porphyry cut the sedimentary rocks and strike parallel to the fold axes. The ore deposits are gold-quartz veins in east-trending fissures. Gold occurs in sulfides, in tellurides, and as native gold.