Where is Lewis County?

7 Lewis Counties in 7 states · 170,906 people (2025)

There are 7 counties named Lewis County in the United States, in Idaho, Kentucky, Missouri, New York, Tennessee, Washington and West Virginia. The most populous is Lewis County, Washington (county seat: Chehalis), with 88,062 people in 2025. 5 of them are named after Meriwether Lewis, American explorer (1774-1809).

All 7 Lewis Counties

Sorted by state. Each link opens the county's map.

State	County seat	Population 2025	Land area (sq mi)	Established	Named after
Lewis County, Idaho	Nezperce	3,704	479	1911	Meriwether Lewis
Lewis County, Kentucky	Vanceburg	12,901	483	1806	Meriwether Lewis
Lewis County, Missouri	Monticello	9,879	505	1833	Meriwether Lewis
Lewis County, New York	Lowville	26,479	1,276	1805	Morgan Lewis
Lewis County, Tennessee	Hohenwald	13,487	282	1843	Meriwether Lewis
Lewis County, Washington	Chehalis	88,062	2,403	1845	Meriwether Lewis
Lewis County, West Virginia	Weston	16,394	387	1816	Charles Lewis

Questions about Lewis Counties

How many Lewis Counties are there?

There are 7 Lewis Counties in the United States, in Idaho, Kentucky, Missouri, New York, Tennessee, Washington and West Virginia.

Which Lewis County is the largest?

By population, Lewis County, Washington (88,062 people in 2025). By land area, Lewis County, Washington (2,403 sq mi).

Which Lewis County is the oldest?

Lewis County, New York, established in 1805. The newest is Lewis County, Idaho (1911).

Why are there so many Lewis Counties?

5 of the 7 are named after Meriwether Lewis, American explorer (1774-1809). Many counties took their names from the same founders, presidents and generals as new states were organized.

How do I find out which Lewis County an address is in?

Open the county map of the state: it has a search box for cities, towns and ZIP codes. On a phone, the "what county am I in" tool on our sister site uses your location.

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