When was Salt Lake County founded?

Salt Lake County was founded in 1850, formed from Tuilla County and Tooele County, and named after Great Salt Lake, Utah.

What is the county seat of Salt Lake County?

The county seat of Salt Lake County is Salt Lake City.

Is there an online parcel map for Salt Lake County?

Yes. A public source publishes a parcel map of 406,698 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Salt Lake County's boundary or name changed?

Salt Lake County was created in 1850 from Tuilla County and Tooele County. Since then the Atlas of Historical County Boundaries records 14 later changes, chiefly involving Green River County, Davis County and Summit County. It was formerly called Great Salt Lake.

Is my lot in a flood zone?

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

County · code 49035

Salt Lake CountyUtah

Salt Lake County is a county in Utah, with its seat in Salt Lake City, formed in 1850.

Founded1850
County seatSalt Lake City
Named forGreat Salt Lake, Utah
Land area742 sq mi + 64 sq mi water
Population1,185,238 2020 Census
Parcels mapped406,698 checked 14 October 2026

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

Updated 20 October 2026

Census outline · seat marked

History

Formed in 1850 from Tuilla County and Tooele County

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

Created by the state of Deseret in 1850 as Great Salt Lake County, it was named after the Great Salt Lake. The county gained and lost territory over several decades, including losing land to the creation of Davis and Summit counties, gaining territory back from Davis in 1855, and having Carson and Green River counties temporarily attached. Great Salt Lake County was renamed Salt Lake County in 1868.

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

1850
Salt Lake County created Great Salt Lake (now Salt Lake) created by the state of Deseret. Tuilla (now Tooele) not fully organized, attached to Great Salt Lake "for judicial, revenue, and election purposes."
from Tuillafrom Tooele
31 January 1850 · Morgan, 47-48, 144; HRS Utah, Weber, 9
1850
Lost territory Great Salt Lake (now Salt Lake) lost to creation of Davis by the state of Deseret.
to Davis
5 October 1850 · Morgan, 54-55, 152-153
1851
Eliminated The state of Deseret was dissolved by its General Assembly, upon recommendation of Brigham Young. State of Deseret counties, including Great Salt Lake (now Salt Lake), continued to operate. 5 April 1851 · Brown, Cannon, and Jackson, 90; Powell, 139
1868
Renamed Great Salt Lake renamed Salt Lake.
formerly Great Salt Lake
29 January 1868 · Utah Terr. Laws 1868, 17th sess., ch. 3/p. 2
1896
Became part of Utah Salt Lake became a county in the state of Utah. 4 January 1896 · U.S. Stat., vol. 28, ch. 138 [1894]/pp. 107-112; U.S. Stat., vol. 29, procl. no. 9, [1896]/pp. 876-877; Van Zandt, 159

Show all 17 changes (12 more)

1850
Salt Lake County created Great Salt Lake (now Salt Lake) created by the state of Deseret. Tuilla (now Tooele) not fully organized, attached to Great Salt Lake "for judicial, revenue, and election purposes."
from Tuillafrom Tooele
31 January 1850 · Morgan, 47-48, 144; HRS Utah, Weber, 9
1850
Lost territory Great Salt Lake (now Salt Lake) lost to creation of Davis by the state of Deseret.
to Davis
5 October 1850 · Morgan, 54-55, 152-153
1851
Eliminated The state of Deseret was dissolved by its General Assembly, upon recommendation of Brigham Young. State of Deseret counties, including Great Salt Lake (now Salt Lake), continued to operate. 5 April 1851 · Brown, Cannon, and Jackson, 90; Powell, 139
1851
Changed Tooele (originally Tuilla) fully organized; detached from Great Salt Lake (now Salt Lake).
TooeleTuilla
10 June 1851 · Tooele County Daughters of Utah Pioneers, 24
1852
Boundary clarified Great Salt Lake (now Salt Lake) boundaries redefined by Utah Territory. Great Salt Lake gained from Tooele and non-county area; exchanged with Utah; lost to Davis. Great Salt Lake included parts of present Utah and Colorado. Green River (Utah Territory, extinct) and Islands in the Great Salt Lake south of Weber were attached to Great Salt Lake "for election, revenue, and judicial purposes."
with Tooele with Utah with Davis with Green Riverwith Weberno change
3 March 1852 · Utah Terr. Laws 1851, 1st sess., secs. 4-6/pp. 162-163
1854
Lost territory Great Salt Lake (now Salt Lake) lost to Green River (Utah Territory, extinct) and lost to creation of Summit; Great Salt Lake eliminated from present Colorado. Summit not fully organized, attached to Great Salt Lake "for election, revenue, and judicial purposes."
to Green Riverto Summit
13 January 1854 · Utah Terr. Laws 1853, 3d sess./pp. 14-15
1854
Changed Green River (Utah Territory, extinct) fully organized, detached from Great Salt Lake (now Salt Lake).
Green River
15 June 1854 · Gowans and Campbell, 63
1855
Gained territory Great Salt Lake (now Salt Lake) gained from Davis.
from Davis
10 January 1855 · Utah Terr. Laws 1854, 4th sess., ch. 85/pp. 279-280
1857
Changed Carson (Utah Territory, extinct) was disorganized and attached to Great Salt Lake (now Salt Lake) "for election, revenue and judicial purposes."
Carson
14 January 1857 · Utah Terr. Laws 1856, 6th sess., pp. 11-14
1857
Changed Green River (Utah Territory, extinct) was disorganized and attached to Great Salt Lake (now Salt Lake) "for election, revenue and judicial purposes" because most settlers had left the area.
Green River
22 December 1857 · Utah Terr. Laws 1857, 7th sess., p. 1
1859
Changed Carson (Utah Territory, extinct) and Green River (Utah Territory, extinct) were reorganized and detached from Great Salt Lake (now Salt Lake).
CarsonGreen River
17 January 1859 · Utah Terr. Laws 1858, 8th sess., ch. 11/pp. 19-20
1861
Changed Summit fully organized; detached from Great Salt Lake (now Salt Lake).
Summit
4 March 1861 · Summit County Record Book A, p. 1
1862
Gained territory Great Salt Lake (now Salt Lake) gained from Cedar (Utah Territory, extinct) and Davis; exchanged with Utah; lost to Summit and Tooele, and lost to creation of Morgan and Wasatch. All islands in Great Salt Lake were attached to Great Salt Lake "for election, revenue, and judicial purposes."
from Cedar from Davis from Utah from Summit from Tooele from Morganfrom Wasatch
17 January 1862 · Utah Terr. Laws 1861, 11th sess., secs. 9, 18/pp. 48, 50
1866
Boundary clarified Great Salt Lake (now Salt Lake) boundaries were redefined (no change).
no change
10 January 1866 · Utah Terr. Laws 1865, 15th sess., ch. 146, secs. 12-13/p. 208
1868
Renamed Great Salt Lake renamed Salt Lake.
formerly Great Salt Lake
29 January 1868 · Utah Terr. Laws 1868, 17th sess., ch. 3/p. 2
1880
Gained territory Salt Lake gained part of the islands and waters of Great Salt Lake that had previously been attached to Salt Lake. 18 February 1880 · Utah Terr. Laws 1880, 24th sess., ch. 14, sec. 1/pp. 15-16
1896
Became part of Utah Salt Lake became a county in the state of Utah. 4 January 1896 · U.S. Stat., vol. 28, ch. 138 [1894]/pp. 107-112; U.S. Stat., vol. 29, procl. no. 9, [1896]/pp. 876-877; Van Zandt, 159

Land and parcels

What the maps cover in Salt Lake

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

Parcels Good enough

Lot lines and tax-map numbers for 406,698 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 31 October 2023 · checked 14 October 2026
Address points Missing

No public address points layer found for Salt Lake 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

Salt Lake by the Census

Population

1,185,238 2020 Census count

Housing units

428,279 2020 Census count

Land area

742 square miles

Water area

64 square miles

People per sq mi

1,597 population ÷ land area

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

See your own lot on these maps

Open Salt Lake 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.

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Questions

Common questions about Salt Lake County

When was Salt Lake County founded?: Salt Lake County was founded in 1850, formed from Tuilla County and Tooele County, and named after Great Salt Lake, Utah.
What is the county seat of Salt Lake County?: The county seat of Salt Lake County is Salt Lake City.
Is there an online parcel map for Salt Lake County?: Yes. A public source publishes a parcel map of 406,698 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Salt Lake County's boundary or name changed?: Salt Lake County was created in 1850 from Tuilla County and Tooele County. Since then the Atlas of Historical County Boundaries records 14 later changes, chiefly involving Green River County, Davis County and Summit County. It was formerly called Great Salt Lake.
Is my lot in a flood zone?: We do not have flood maps for Salt Lake 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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