County · code 06051
Mono CountyCalifornia
Mono County is a county in California with its seat in Bridgeport. It was formed on April 24, 1861, from parts of Calaveras, Fresno, and Mariposa counties and was named after the Mono people and Mono Lake.
- Founded1861
- County seatBridgeport
- Named forMono people and Mono Lake, California
- Land area3,049 sq mi + 83 sq mi water
- Population13,195 2020 Census
- Parcels mapped20,494 checked 15 October 2026
Where it is
Mono on the map of California
California has 58 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Formed in 1861 from Calaveras County, Frezno County, Fresno County and Mariposa County
An old deed may name a county that no longer exists, or a boundary that has since moved.
Mono County was created from Calaveras, Fresno, and Mariposa counties on April 24, 1861, with its original county seat at Aurora, which lay in Nevada Territory due to boundary uncertainty between California and Nevada. Over the following years, Mono County's boundaries shifted as Alpine County was created from part of it in 1864, and Inyo County was formed from Mono territory in 1866, though Mono also gained territory from other counties during this period.
- 1861Mono County created Mono created from Calaveras, Frezno (now Fresno), and remnant of Mariposa. Due to uncertainty about the precise location of the boundary between California and Nevada Territory, the county seat of Mono, Aurora, was actually located in Nevada. · Calif. Stats. 1861, 12th sess., ch. 233/pp. 235-236; Chappell, 239-242; "Reddy v. Tinkum," in Calif. Rpts., 60:458-467
- 1864Lost territory Mono lost to creation of Alpine. · Calif. Stats. 1863-1864, 15th sess., ch. 180/pp. 178-182
- 1864
- 1866Gained territory Mono gained remnant of Amador that was left separate from the rest of Amador after the creation of Alpine. · Calif. Stats. 1865, 16th sess., ch. 161/p. 144
- 1866Lost territory Mono lost to creation of Inyo; Inyo boundaries were identical to those of Coso (proposed).to Inyoto Coso· Calif. Stats. 1865, 16th sess., ch. 316/pp. 355-358
- 1870Gained territory Mono gained from Tulare the remnant of territory that was separated from Tulare by the creation of Inyo on 22 March 1866. · Calif. Stats. 1869, 18th sess., ch. 18/p. 20
- 1870
Land and parcels
What the maps cover in Mono
Who publishes each layer, how good it is, and when we last checked.
-
Parcels Good enough
Lot lines and tax-map numbers for 20,494 parcels from Mono County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 15 October 2026 -
Address points Missing
No public address points layer found for Mono County yet.
-
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
Mono 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.
Permits
- Health department: septic and well
Behavioral Health
- Permit Fees
- Forms & Permits
Zoning and code
GIS and maps
County government
- County government
The official website of Mono County.
See your own lot on these maps
Open Mono 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 Mono County
- When was Mono County founded?
- Mono County was founded in 1861, formed from Calaveras County, Frezno County, Fresno County and Mariposa County, and named after Mono people and Mono Lake, California.
- What is the county seat of Mono County?
- The county seat of Mono County is Bridgeport.
- Is there an online parcel map for Mono County?
- Yes. Mono County publishes a parcel map of 20,494 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Mono County's boundary or name changed?
- Mono County was created in 1861 from Calaveras County, Frezno County, Fresno County and Mariposa County. Since then the Atlas of Historical County Boundaries records 6 later changes, chiefly involving Inyo County, Alpine County and Coso County.
- Who issues building permits in Mono County?
- The county's page on building permits: Permit Fees. Inside a city or town, ask that city first.
- Who issues septic and well permits in Mono County?
- The county's page on septic systems and wells: Behavioral Health.
- Is my lot in a flood zone?
- We do not have flood maps for Mono County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby