Pierce County is located on Puget Sound in Washington State. It is bordered on the west by Thurston County, the north by King County, the east by Yakima County and the south by Lewis County. As of the 2010 U.S. Census, Pierce County had a total land area of 1,669.51 square miles and a population of 795,225. Tacoma is the largest city with a population of 198,397. Also of interest:
- Intersecting watershed sub-basins(5): Naches, Upper Cowlitz, Puyallup, Nisqually and Puget Sound.
- Major lakes: Alder Lake, Lake Tapps, American Lake, Spanaway Lake and Steilacoom Lake.
- Major rivers: Puyallup River, Carbon River, Nisqually River, Clearwater River, White River, Mowich River and Mashel River.
- Mount Rainier (14,410 feet) is part of the Cascade Range and the highest point in Pierce County. Being the tallest mountain and one of five major composit volcanoes (sometimes called stratovolcanoes) located in the state, makes Mount Rainier an icon of the Washington landscape.
A report from the Tacoma-Pierce County Health Department describes the results of a project to address threats to water quality in Pierce County, focusing on shellfish areas most at risk.
A July 2014 report examines potential human wellbeing indicators for the Puyallup Watershed.
A 2014 report describes a research and monitoring study of Pigeon Guillemot conducted in and near the Nisqually Reach Aquatic Reserve.