Powderhouse Creek is a tributary of Mouse Creek joining at river mile 0.8. Mouse Creek then flows into an off-channel slough. Mouse Creek flows into the Sauk River just below Darrington. The project involved redirecting 330 feet (100 m) of stream channel. Instream structures were built into the channel (27 structures including rock weirs and log weirs), and spawning gravel was added to the streambed. In 1999, native trees and shrubs (617) were planted along 330 feet (100 m) of both stream banks, and 1,200 feet (366 m) of fencing was installed to exclude a horse pasture. Powderhouse Creek is a WDFW index stream and is utilized by the same fish species at Mouse Creek though in lesser numbers.

Four years after the project was completed, numbers of coho observed during surveys varied considerably. The first winter after project completion (1998-99), 4 live coho and 1 coho redd were counted. Coho returns increased in 1999-00 to 14 live and 6 redds, but decreased sharply in 2000-01 to no live coho, 1 carcass, and 2 redds. The coho numbers increased againin 2001-02 when 102 live, 30 carcasses, and 13 coho redds were observed. During the winter of 2002-03 there were 60 live coho, one coho carcass, and 27 coho redds recorded on Powderhouse Creek. During the Fall of 2003 Powderhouse Creek filled up entirely with gravel and was forced to change course, making the stream inaccessible to returning salmonids. The surveys of 2003-04 showed no live, no carcasses, and no redds in this reach. However, prior to the 2004-05 spawning season the stream had corrected itself and was once again accessible to 50 live coho, 2 coho carcasses, 26 coho redds, and three live cutthroat trout. During the 2005-06 spawning season 8 live coho, 1 coho carcasses, and 2 coho redds were observed on Powderhouse Creek.