Pigeon Hill was so named for the abundance of pigeons that roosted there, and fed on the spilled grain of the nearby flour mill. (Seattle Department of Engineering. SWSHS/Log House Museum FIC2006.0936)- Columbia River drainage basin (Wikipedia)
The Columbia River drainage basin is the drainage basin of the Columbia River in the Pacific Northwest region of North America. It covers 668,000 km2 or 258,000 sq mi. In common usage, the term often refers to a smaller area, generally the portion of the drainage basin that lies within eastern Washington.