|Elevation||1,795 ft (547 m)|
|Time zone||UTC-8 (Pacific (PST))|
|• Summer (DST)||UTC-7 (PDT)|
|GNIS feature ID||1521147|
Impach is located at the mouth of a long coulee in rural Seylor Valley approximately 3 miles (5 km) west of Inchelium on County Highway 2, also known as Bridge Creek Road. Two prominent summits, Stranger Mountain, 3,021 feet (921 m), and Monument Butte, 2,057 feet (627 m), overlook Impach less than 2 miles (3 km) to the south.
Historically, Impach has been the site of traditional Native American dance ceremonies by members of the confederated tribes. Gold was discovered in Ferry County in 1896 and several gold mines operated in the Impach area as late as the 1950s, including the nearby Gold Twenty Mine which produced lode gold, lead, and silver. During the early 1930s, a predecessor of the Works Progress Administration established a small logging operation in Impach, which brought some unemployed families to the area at the height of the Great Depression. A United States post office operated at Impach, Washington, from 1922 to 1954. The scenic valley is primarily grazing land today.
- U.S. Geological Survey Geographic Names Information System: Impach, Washington
- USGS Geographic Names Information System (GNIS), Impach, Washington
- Impach, Washington WA Community Profile / Ferry County, WA Data
- AnyplaceAmerica.com, Topographic Map Search: Impach, Washington
- Tacoma Public Library, Washington Place Names Database Archived 2012-07-23 at Archive.today: "Impach"
- Washington State University Libraries Digital Collection, State history. Native Americans. Celebrations, picnics & pow wows. 1937-01-22, newspaper article
- Washington State University Libraries Digital Collection, State history. Native Americans. Ceremonies. 1937-01-28, newspaper article
- Washington Gold, Ferry County Washington Gold, "Meteor"
- Jim Forte Postal History: Post Office, Washington, Ferry County: Impach (1922-1954)