When was Coos County founded?

Coos County was founded in 1853, formed from Jackson County and Umpqua County, and named after Coos people.

What is the county seat of Coos County?

The county seat of Coos County is Coquille.

Is there an online parcel map for Coos County?

Yes. A public source publishes a parcel map of 42,486 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Coos County's boundary or name changed?

Coos County was created in 1853 from Jackson County and Umpqua County. Since then the Atlas of Historical County Boundaries records 9 later changes, chiefly involving Douglas County and Curry County.

Who issues building permits in Coos County?

The county's page on building permits: Alarm Permits - Coos County. Inside a city or town, ask that city first.

Who issues septic and well permits in Coos County?

The county's page on septic systems and wells: Health department: septic and well.

Is my lot in a flood zone?

We do not have flood maps for Coos County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 41011

Coos CountyOregon

Coos County is a county in Oregon with its seat in Coquille, formed on December 22, 1853. The county was named after the Coos people and formed from Jackson and Umpqua counties.

Founded1853
County seatCoquille
Named forCoos people
Land area1,596 sq mi + 210 sq mi water
Population64,929 2020 Census
Parcels mapped42,486 checked 16 October 2026

Open the free map Click any parcel in Coos County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 20 October 2026

Census outline · seat marked

History

Formed in 1853 from Jackson County and Umpqua County

An old deed may name a county that no longer exists, or a boundary that has since moved.

Coos County was formed in 1853 from Jackson County and Umpqua County, and named after Coos people. Coquille is the county seat.

Deeds and plats from before 1853 for land now in Coos County may have been recorded in Jackson County and Umpqua County.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries; the 5 that matter most are shown first.

1853
Coos County created Coos created by Oregon Territory from Jackson and Umpqua (extinct); Coos not fully organized, attached to Umpqua "for judicial purposes."
from Jacksonfrom Umpqua
22 December 1853 · Ore. Terr. Special Laws, 1853, 5th reg. sess., p. 13; Ore. Terr. Rev. Stat. 1853, p. 63
1855
Lost territory Coos lost to creation of Curry.
to Curry
18 December 1855 · Ore. Terr. Laws 1855-1856, 7th reg. sess., p. 49
1856
Lost territory Coos lost Cammas Prairie to Douglas.
to Douglas
18 December 1856 · Ore. Terr. Laws 1856-1857, 8th reg. sess., p. 80
1859
Became part of Oregon Coos became an Oregon county when the state of Oregon was admitted to the Union and Oregon Territory was eliminated. 14 February 1859 · U.S. Stat., vol. 11, ch. 33[1859], secs. 1-2/pp. 383-384; Ore. Laws 1860, 1st reg. sess., pp. 28-30
1863
Exchanged territory Coos exchanged with Douglas. Act approved 16 October 1862; became effective 6 July 1863.
with Douglas
6 July 1863 · Ore. Laws 1862, 2nd reg. sess., p. 59

Show all 13 changes (8 more)

1853
Coos County created Coos created by Oregon Territory from Jackson and Umpqua (extinct); Coos not fully organized, attached to Umpqua "for judicial purposes."
from Jacksonfrom Umpqua
22 December 1853 · Ore. Terr. Special Laws, 1853, 5th reg. sess., p. 13; Ore. Terr. Rev. Stat. 1853, p. 63
1855
Lost territory Coos lost to creation of Curry.
to Curry
18 December 1855 · Ore. Terr. Laws 1855-1856, 7th reg. sess., p. 49
1856
Lost territory Coos lost Cammas Prairie to Douglas.
to Douglas
18 December 1856 · Ore. Terr. Laws 1856-1857, 8th reg. sess., p. 80
1859
Became part of Oregon Coos became an Oregon county when the state of Oregon was admitted to the Union and Oregon Territory was eliminated. 14 February 1859 · U.S. Stat., vol. 11, ch. 33[1859], secs. 1-2/pp. 383-384; Ore. Laws 1860, 1st reg. sess., pp. 28-30
1863
Exchanged territory Coos exchanged with Douglas. Act approved 16 October 1862; became effective 6 July 1863.
with Douglas
6 July 1863 · Ore. Laws 1862, 2nd reg. sess., p. 59
1864
Exchanged territory Coos exchanged with Douglas.
with Douglas
21 October 1864 · Ore. Laws 1864, 3rd reg. sess., p. 44
1872
Gained territory Coos gained from Curry.
from Curry
28 October 1872 · Ore. Laws 1872, 7th reg. sess., pp. 183-184
1878
Gained territory Coos gained from Douglas.
from Douglas
19 October 1878 · Ore. Special Laws 1878, 10th reg. sess., pp. 162-164
1882
Exchanged territory Coos exchanged with Douglas.
with Douglas
16 October 1882 · Ore. Special Laws 1882, 12th reg. sess., pp. 83-84
1951
Exchanged territory Coos exchanged with Curry when boundary was redefined to run along township and range lines instead of ridge line.
with Curry
30 April 1951 · Ore. Laws 1951, 46th reg. sess., ch. 422/pp. 684-687
1951
Boundary clarified Coos boundary with Curry clarified to correct an error in the boundary description of 30 April 1951 (no change).
with Curryno change
8 May 1951 · Ore. Laws 1951, 46th reg. sess., ch. 494/p. 864
1983
Lost territory Coos lost very small area in T 28 South / R 9 West / Sec. 36 to Douglas. Coos boundary with Curry redefined to amend description in Oregon Revised Statutes. Became effective 90 days after the end of the legislative session on 16 July (no change).
to Douglas to Curry
14 October 1983 · Ore. Laws 1983, 62nd reg. sess., ch. 778/pp. 1514-1515
1999
Gained territory Coos gained small area from Douglas when boundary was redefined to run along range line. Coos boundary with Curry was redefined (no change).
from Douglas from Curry
23 October 1999 · Ore. Laws 1999, 70th reg. sess., ch. 600/pp. 1396-1399

Land and parcels

What the maps cover in Coos

Who publishes each layer, how good it is, and when we last checked.

Parcels Good enough

Lot lines and tax-map numbers for 42,486 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 11 August 2026 · checked 16 October 2026
Address points Official

One point per address, 30,717 in all from State of Oregon — Department of Administrative Services Geospatial Enterprise Office (GEOHub) with Oregon Department of Emergency Management 9-1-1 program.
edited 16 January 2026 · checked 13 October 2026
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Coos by the Census

Population

64,929 2020 Census count

Housing units

31,378 2020 Census count

Land area

1,596 square miles

Water area

210 square miles

People per sq mi

41 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Who to ask before you build, dig or sell

Official county pages only. We link to them; we do not copy them, because they change.

Inside a city or town, permits usually come from that city rather than the county.

Permits

Health department: septic and wellfrom co.coos.or.us · checked 13 October 2026
Alarm Permits - Coos Countyfrom co.coos.or.us
Firewood Permit Hotline - Coos Countyfrom co.coos.or.us
Onsite Septic Programfrom cooscounty-or.specialdistrict.org

Zoning and code

CCZLDO - Zoning and Land Development Ordinancefrom cooscounty-or.specialdistrict.org
Land Use Ordinance - Article 7 - Roadsfrom cooscounty-or.specialdistrict.org
Maps - Zoning and Development - Coos Countyfrom co.coos.or.us

GIS and maps

County GIS and maps 888-275-6368from co.coos.or.us · checked 13 October 2026

County government

County government
The official website of Coos County.
co.coos.or.us

See your own lot on these maps

Open Coos County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Coos County

When was Coos County founded?: Coos County was founded in 1853, formed from Jackson County and Umpqua County, and named after Coos people.
What is the county seat of Coos County?: The county seat of Coos County is Coquille.
Is there an online parcel map for Coos County?: Yes. A public source publishes a parcel map of 42,486 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Coos County's boundary or name changed?: Coos County was created in 1853 from Jackson County and Umpqua County. Since then the Atlas of Historical County Boundaries records 9 later changes, chiefly involving Douglas County and Curry County.
Who issues building permits in Coos County?: The county's page on building permits: Alarm Permits - Coos County. Inside a city or town, ask that city first.
Who issues septic and well permits in Coos County?: The county's page on septic systems and wells: Health department: septic and well.
Is my lot in a flood zone?: We do not have flood maps for Coos County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

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