Pg. 113-150. Bill's Creek beds. Largely thin-bedded shale, with a few thin layers of interbedded argillaceous limestone, highly fossiliferous. Chief exposures on Bill's Creek and along eastern shore of Little Bay de Noc, Delta County, northern Michigan. Total thickness about 88 feet. The lowest beds of Upper Ordovician Richmond formation of Stonington region of Michigan. Disconformably overlain by Bay de Noc member of Stonington beds. Lower part of the beds may not belong to the Richmond.
Type locality: along Bill's Creek, 5 mi northeast of Rapid River, in sec. 7, T. 41 N., R. 20 W., and in sec. 12, T. 41 N., R. 21 W., [Rapid River 15-min quadrangle], Delta Co., northern MI.

Source: US geologic names lexicon (USGS Bull. 896, p. 188-189).

Pg. 13, 14 (table), 40-45. Bill's Creek beds of Richmond formation. Overlie Haymeadow Creek member (new) of Trenton formation. Unit termed Haymeadow Creek was formerly included in basal Bill's Creek beds. Maximum thickness of beds 80 feet; lower 20 feet are now correlated with Collingwood which some workers consider late Trenton. Thickness at type locality about 62 feet. Underlie Stonington beds [or member] of Richmond. Contact with overlying Stonington beds is disconformable. Age is Late Ordovician.
Type locality: along Bill's Creek, 5 mi northeast of Rapid River, in sec. 7, T. 41 N., R. 20 W., and in sec. 12, T. 41 N., R. 21 W., [Rapid River 15-min quadrangle], Delta Co., northern MI.

Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 344).

Chart 2 (column 46). Chart shows Bill's Creek shale below Bay de Noc limestone. Age is Late Ordovician (Cincinnatian; Richmondian).

Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 344).