The largest county is Okanagan County, with a total area of 13644 km2 (5315 square miles).
Second is Yakima County at 11168 km2 (4312 square miles).
Third is Chelan County at 7754 km2 (2994 square miles).
The largest county in Washington state by population is King County. It is home to Seattle and has the highest population in the state.
The largest by far is King County which includes metropolitan Seattle. As of the 2010 census its population was 1,931,249.
According to census.gov, King County, Washington, has the most population at 1,859,284 people in 2007.According to "Washington State" history book: King County with 1,685,600 as of 2000.
As of 2021, the population of Pierce County, Washington is estimated to be around 900,300 people. It is the second most populous county in the state of Washington.
That would be Multnomah county, though smallest in area of the 36 Oregon counties, it is the most populous as its county seat, Portland, is the state's largest city. In 2010, the county had a population of 735,334.
Wayne County is the largest county in Michigan. It is home to the city of Detroit and has a significant population compared to other counties in the state.
Cumberland County in Maine has the highest population compared to other counties in the state. Its county seat is Portland, which is the largest city in Maine.
The largest county by population is King. The largest in size is Okanogan, 5,268 square miles.
Fairfax County with an estimated population of 1,037,065 as of 2009. The county is located in the far northern part of the state and is a suburb of Washington, DC.
A county is an administrative division of a state. As of 2014, the largest county in population in Tennessee is Shelby County.
Hinds County is the county in Mississippi with the largest population. Hinds County includes Jackson, the state capital and the most populous city in the state.
Maricopa county
Colorado's largest county is the city and county of Denver (which is also the largest city in the state) and the 2009 population was 610, 345
There are 39 counties in the state of Washington. Based on population the largest counties in Washington are King County, Pierce County, Snohomish County, Spokane County and Clark County.
Washington.
The largest county in the state of Wyoming is Sweetwater County with a population of 43,806 people. Wyoming's total population is 582,658.
South Dakota is a state. The largest county by size (area) in South Dakota is Meade County. The largest county by population is Minnehaha County which contains the state's largest city, Sioux Falls.
Washington with a population of 6,724,540.
The largest county by population in Wyoming is Laramie County. The population estimate for Laramie County for 2012 was 94,627. Laramie County's seat is Cheyenne, which is also the state capital and the largest city in Wyoming by population.