County · code 16051
Jefferson CountyIdaho
Jefferson County is a county in Idaho with its seat in Rigby, formed in 1913.
- Founded1913
- County seatRigby
- Named forThomas Jefferson
- Land area1,094 sq mi + 12 sq mi water
- Population30,891 2020 Census
- Parcels mapped17,927 checked 16 October 2026
Where it is
Jefferson on the map of Idaho
Idaho has 44 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Formed in 1913 from Fremont County
An old deed may name a county that no longer exists, or a boundary that has since moved.
Jefferson County was created from Fremont County on November 4, 1913, following voter approval in that year's general election. The county was named after Thomas Jefferson. In 1917, Jefferson County lost territory to the newly created Butte County.
- 1913Jefferson County created Jefferson created from Fremont. Act approved 18 February 1913, became effective through a vote in the general election of 4 November 1913. · Id. Laws 1913, 12th sess., ch. 25/pp. 94-107; Id. Code Ann. (1996), vol. 6, ch. 1, sec. 31-128 "Jefferson Co."/pp. 38; Nelson and Webbert, p. 88
- 1917Lost territory Jefferson lost to creation of Butte. · Id. Laws 1917, 14th sess., ch. 98/pp. 344-360
Land and parcels
What the maps cover in Jefferson
Who publishes each layer, how good it is, and when we last checked.
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Parcels Good enough
Lot lines and tax-map numbers for 17,927 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 Missing
No public address points layer found for Jefferson County yet.
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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
Jefferson by the Census
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.
Zoning and code
County government
- County government
The official website of Jefferson County.
See your own lot on these maps
Open Jefferson 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.
Questions
Common questions about Jefferson County
- When was Jefferson County founded?
- Jefferson County was founded in 1913, formed from Fremont County, and named after Thomas Jefferson.
- What is the county seat of Jefferson County?
- The county seat of Jefferson County is Rigby.
- Is there an online parcel map for Jefferson County?
- Yes. Idaho Department of Water Resources publishes a parcel map of 17,927 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Jefferson County's boundary or name changed?
- Jefferson County was created in 1913 from Fremont County. Since then the Atlas of Historical County Boundaries records 1 later change, chiefly involving Butte County.
- Who issues building permits in Jefferson County?
- The county's page on building permits: Planning, Zoning & Building Permits & Applications. Inside a city or town, ask that city first.
- Is my lot in a flood zone?
- We do not have flood maps for Jefferson County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby