Browse / United States / Washington / Cosmopolis
Cosmopolis
Washingtoncity
Total population
2,202
Median home value
$317,000
Bachelor's+
Median income
$84,853
Air quality index
Demographic figures from US Census Bureau · ACS 5-year estimates. Overview below cites Wikipedia and may reference a different year.
City facts
Facts from Wikidata (CC0).
Overview
Cosmopolis is a city in Grays Harbor County, Washington, United States. The population was 1,638 at the 2020 census. It lies on the Chehalis River and U.S. Route 101, immediately southeast of Aberdeen. Cosmopolis historically had an economy that centered around its pulp mill, which closed in 2006.
Read more on WikipediaHistory & geography
History
The area around the mouth of the Chehalis River is the ancestral home of indigenous Coast Salish peoples who are today referred to as the Lower Chehalis. The first white settler in the area, James Pilkington, staked a Donation Land Act claim to on the south bank of the river in 1852. The site was later used for unsuccessful negotiations between indigenous representatives and the Washington territorial government for the 1855 Chehalis River Treaty. Pilkington built a cabin on the land, but later sold the property in 1853 to Kentucky-born emigrants David F. Byles and Austin E. Young. Byles and Young proposed a plat for a town named Cosmopolis on the south bank of the Chehalis River. The origin of the name is unclear; one account is that it came from an indigenous chief's name, and another claims that an earlier settler asked for a name that means "city of the whole world". Cosmopolis was platted in 1861 and is considered the oldest modern settlement in Grays Harbor County (then known as Chehalis County). Several settlers had attempted to build the townsite as planned, but failed due to various business issues. A lumber mill opened in 1881 and soon became profitable, bringing other businesses to Cosmopolis, which was incorporated as a town in 1891. The Northern Pacific Railway constructed a spur line through the new town in 1892 that traveled across a bridge to Junction City on the north side of the Chehalis River, with onward connections to Tacoma. The mill grew in the early 20th century under various owners until it was sold to Weyerhaeuser in 1957.
Geography
Cosmopolis lies on the south side of the Chehalis River near its mouth at the head of Grays Harbor, an estuarine bay of the Pacific Ocean. Mill Creek, a short tributary of the Chehalis River, runs through the western part of the city. The city borders Aberdeen to the northwest. This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above . According to the Köppen Climate Classification system, Cosmopolis has a warm-summer Mediterranean climate, abbreviated "Csb" on climate maps.
Excerpted from the corresponding Wikipedia article (CC BY-SA).
Demographics & economy
Race & ethnicity
Source: US Census Bureau — American Community Survey, 5-year estimates.
Geography
Coordinates & boundaries from the US Census TIGER/Line shapefiles.
Climate
Air quality
Current readings from Open-Meteo Air Quality API (Copernicus CAMS European reanalysis).
Industrial & pollution facilities
Natural hazard risk
Health (adults)
Age-adjusted prevalence estimates from CDC PLACES (latest release).
Walkability
Amenities nearby
Wildlife & biodiversity
Most-observed species
- American CrowCorvus brachyrhynchos C.L.Brehm, 1822 · Aves3,430
- Song SparrowMelospiza melodia (A.Wilson, 1810) · Aves3,306
- Canada Goose (canadensis Group)Branta canadensis (Linnaeus, 1758) · Aves3,256
- MallardAnas platyrhynchos Linnaeus, 1758 · Aves3,004
- American RobinTurdus migratorius Linnaeus, 1766 · Aves2,923
- European StarlingSturnus vulgaris Linnaeus, 1758 · Aves2,910
- Great Blue/Cocoi HeronArdea herodias Linnaeus, 1758 · Aves2,268
- Red-winged BlackbirdAgelaius phoeniceus (Linnaeus, 1766) · Aves2,055
Citizen-science & research observations from the Global Biodiversity Information Facility (GBIF).
Schools
Earthquake history
Most recent
- M 2.84 — 2026-05-274 km W of Wauna, Washington
- M 2.86 — 2026-03-112 km W of Home, Washington
- M 2.82 — 2025-12-255 km W of Gorst, Washington
- M 2.65 — 2025-12-195 km WSW of Pe Ell, Washington
- M 2.84 — 2025-10-0921 km NW of Hoodsport, Washington
- M 2.84 — 2025-05-1325 km WNW of Hoodsport, Washington
Events from the USGS Earthquake Catalog (global) (FDSN Event Web Service).
Photos
Sights & places nearby
Notable people from here









People born within ~10 km, from Wikidata (CC0). Click any name for their Wikipedia article.
Nearby places in Washington
Geography & sun
Elevation, sunrise/sunset and daylight from Open-Meteo. Solar climatology from NASA POWER.
Nearby airports
Public attention
Pageview totals from the Wikimedia Pageviews API.
Books about Cosmopolis

Search results from Open Library.
Recent natural events nearby
- Wildfire HIGH LAVA, Skamania, WashingtonWildfires · 2026-07-23 · 108 mi
- Wildfire THREE QUEENS, Kittitas, WashingtonWildfires · 2026-07-16 · 122 mi
- Wildfire RANSIER, Yakima, WashingtonWildfires · 2026-07-26 · 149 mi
- Wildfire Signal Peak, Yakima, WashingtonWildfires · 2026-07-24 · 150 mi
- Wildfire LITTLE GIANT, Chelan, WashingtonWildfires · 2026-07-16 · 155 mi
- Wildfire Austin Non-Stat, Clackamas, OregonWildfires · 2026-08-12 · 159 mi
- Wildfire 8 MILE, Wasco, OregonWildfires · 2026-07-24 · 159 mi
- Wildfire AUSTIN, Clackamas, OregonWildfires · 2026-08-09 · 160 mi
Wildfires, storms and other events from NASA EONET (last 12 months, within 250 mi).
Ground air-quality sensors
Recently spotted species
Nearest stream gauge
Events
Gallery
Sources
- • Wikipedia
- • US Census Bureau (ACS 5-year estimates)
- • Wikidata
- • Open-Meteo Air Quality (CAMS)
- • USGS Earthquake Catalog (global feed)
- • GBIF (Global Biodiversity Information Facility)
- • CDC PLACES
- • Open-Meteo / sunrise-sunset.org
- • Wikipedia Pageviews API
- • Open Library
- • NASA EONET