When was Owyhee County founded?

Owyhee County was founded in 1863, formed from Boise County, and named after Hawaii.

What is the county seat of Owyhee County?

The county seat of Owyhee County is Murphy.

Is there an online parcel map for Owyhee County?

Yes. Idaho Department of Water Resources publishes a parcel map of 10,570 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Owyhee County's boundary or name changed?

Owyhee County was created in 1863 from Boise County. Since then the Atlas of Historical County Boundaries records 5 later changes, chiefly involving Oneida County, Cassia County and Elmore County.

Is my lot in a flood zone?

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

Owyhee County, Idaho: parcels, history and offices

Where it is

Owyhee on the map of Idaho

Idaho has 44 counties and county equivalents, each with its own records office. Shapes with a page are links.

Counties of Idaho · Owyhee highlighted

History

Formed in 1863 from Boise County

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

Owyhee County was created December 31, 1863, by Idaho Territory from Boise County and non-county area, initially extending into present-day Wyoming west of the Rocky Mountains and south of the Snake River. The county lost territory to the creation of Oneida County on January 22, 1864, which eliminated its presence in Wyoming. It continued to lose land through the creation of Cassia County in 1879 and Elmore County in 1930.

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

1863
Owyhee County created Owyhee created by Idaho Territory from Boise and Non-County Area 2; included parts of present Idaho and Wyoming.
from Boise
31 December 1863 · Id. Terr. Laws 1863, loc. and spec., 1st sess., p. 624
1864
Lost territory Owyhee lost to creation of Oneida.
to Oneida
22 January 1864 · Id. Terr. Laws 1863, loc. and spec., 1st sess., p. 625
1871
Lost territory Oywhee lost to Oneida.
to Oywheeto Oneida
2 January 1871 · Id. Terr. Laws 1870, 6th sess., p. 54
1879
Lost territory Owyhee lost to creation of Cassia.
to Cassia
20 February 1879 · Id. Terr. Laws 1879, 10th sess., pp. 43-46
1890
Became part of Idaho Owyhee continued as an Idaho county when the state of Idaho admitted to the Union and Idaho Territory eliminated. 3 July 1890 · U.S. Stat., vol. 26, ch. 656 [1890]/pp. 215-219; Van Zandt, 156

Show all 9 changes (4 more, mostly small adjustments)

1863
Owyhee County created Owyhee created by Idaho Territory from Boise and Non-County Area 2; included parts of present Idaho and Wyoming.
from Boise
31 December 1863 · Id. Terr. Laws 1863, loc. and spec., 1st sess., p. 624
1864
Lost territory Owyhee lost to creation of Oneida.
to Oneida
22 January 1864 · Id. Terr. Laws 1863, loc. and spec., 1st sess., p. 625
1864
Boundary clarified Owyhee redefined (no change).
no change
4 February 1864 · Id. Terr. Laws 1863, loc. and spec., 1st. sess., sec. 6/p. 630
1871
Lost territory Oywhee lost to Oneida.
to Oywheeto Oneida
2 January 1871 · Id. Terr. Laws 1870, 6th sess., p. 54
1879
Lost territory Owyhee lost to creation of Cassia.
to Cassia
20 February 1879 · Id. Terr. Laws 1879, 10th sess., pp. 43-46
1887
Boundary clarified Owyhee boundaries redefined (no change).
no change
1 June 1887 · Id. Terr. Laws 1887, comp., spec. and loc., 14th sess., p. 195
1890
Became part of Idaho Owyhee continued as an Idaho county when the state of Idaho admitted to the Union and Idaho Territory eliminated. 3 July 1890 · U.S. Stat., vol. 26, ch. 656 [1890]/pp. 215-219; Van Zandt, 156
1930
Lost territory Owyhee lost to Elmore. Act approved 21 Feb 1929, became effective through a vote in the general election of 4 November 1930.
to Elmore
4 November 1930 · Id. Laws 1929, 20th sess., ch. 47/pp. 59-66; Id. Code Ann. (1996), vol. 6, ch. 1, sec. 31-122 "Elmore Co."/p.32
1999
Boundary clarified Owyhee boundaries clarified (no change).
no change
3 March 1999 · Id. Laws 1999, 55th leg., 1st reg. sess., ch. 35/pp. 72-73

Land and parcels

What the maps cover in Owyhee

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

Parcels Good enough

Lot lines and tax-map numbers for 10,570 parcels from Idaho Department of Water Resources. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 16 October 2026
Address points Official

One point per address, 6,053 in all from State of Idaho ArcGIS Online organization (owner pbond__idaho; Idaho Geospatial Council / Idaho Office of Information Technology Services, 'The Idaho Map').
edited 2 October 2026 · checked 14 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

Owyhee by the Census

Population

11,913 2020 Census count

Housing units

4,719 2020 Census count

Land area

7,668 square miles

Water area

29 square miles

People per sq mi

2 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.

Records

Assessor and property records 208-495-2817from owyheecounty.net · checked 13 October 2026

Zoning and code

Planning and zoning 120-833-7454from owyheecounty.net · checked 13 October 2026

County government

County government
The official website of Owyhee County.
owyheecounty.net

See your own lot on these maps

Open Owyhee 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 Owyhee County

When was Owyhee County founded?: Owyhee County was founded in 1863, formed from Boise County, and named after Hawaii.
What is the county seat of Owyhee County?: The county seat of Owyhee County is Murphy.
Is there an online parcel map for Owyhee County?: Yes. Idaho Department of Water Resources publishes a parcel map of 10,570 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Owyhee County's boundary or name changed?: Owyhee County was created in 1863 from Boise County. Since then the Atlas of Historical County Boundaries records 5 later changes, chiefly involving Oneida County, Cassia County and Elmore County.
Is my lot in a flood zone?: We do not have flood maps for Owyhee County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby

Owyhee CountyIdaho