- Jefferson County, Washington has 1,803.7 square miles of land area and is the 18th largest county in Washington by total area. Jefferson County, Washington is bordered by Grays Harbor County, Washington, Kitsap County, Washington, Clallam County, Washington, Island County, Washington, Mason County, Washington, and San Juan County, Washington.
- United States Geological Survey (Wikipedia)
The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on March 3, 1879, to study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The agency also makes maps of extraterrestrial planets and moons based on data from U.S. space probes.