When was St. Croix County founded?

St. Croix County was founded in 1840, formed from Crawford County.

What is the county seat of St. Croix County?

The county seat of St. Croix County is Hudson.

Is there an online parcel map for St. Croix County?

Yes. St. Croix County publishes a parcel map of 54,897 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has St. Croix County's boundary or name changed?

St. Croix County was created in 1840 from Crawford County. Since then the Atlas of Historical County Boundaries records 11 later changes, chiefly involving Bayfield County, La Pointe County and Pierce County.

Who issues building permits in St. Croix County?

The county's page on building permits: Child Labor Permit Information. Inside a city or town, ask that city first.

Who issues septic and well permits in St. Croix 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 St. Croix County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 55109

St. Croix CountyWisconsin

St. Croix County is a county in Wisconsin with its seat in Hudson. It was created on August 3, 1840, from Crawford County by Wisconsin Territory.

Founded1840
County seatHudson
Land area722 sq mi + 13 sq mi water
Population93,536 2020 Census
Parcels mapped54,897 checked 16 October 2026

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

Updated 20 October 2026

Census outline · seat marked

History

Formed in 1840 from Crawford County

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

St. Croix County originally included territory in present-day Minnesota when it was created from Crawford County in 1840. The county lost territory in 1845 when La Pointe County (now Bayfield County) was established, and lost its Minnesota lands when Wisconsin became a state in 1848. St. Croix was fully organized in 1849 and detached from Crawford County for judicial purposes.

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

1840
St. Croix County created St. Croix created by Wisconsin Territory from Crawford and Non-County Area 1 attached to Crawford; St. Croix included territory in present Wisconsin and Minnesota.
from Crawford
3 August 1840 · Wis. Terr. Laws 1839-1840, no. 20, sec. 1/pp. 25-26
1845
Lost territory St. Croix lost to creation of La Pointe (now Bayfield).
to La Pointeto Bayfield
19 February 1845 · Wis. Terr. Laws 1845, pp. 52-53
1848
Lost territory St. Croix lost territory when the state of Wisconsin was created from Wisconsin Territory; St. Croix eliminated from present Minnesota. St. Croix became a county in the state of Wisconsin. 29 May 1848 · U.S. Stat., vol. 9, ch. 89 [1846]/pp. 56-58, and ch. 50 [1848]/pp. 233-235; Van Zandt, 128, 130
1849
Exchanged territory St. Croix exchanged with Chippewa, gained from La Pointe (now Bayfield). An overlap (Overlap Area 3) was created between St. Croix and La Pointe when both counties were assigned the same area.
with Chippewa with La Pointewith Bayfield
8 March 1849 · Wis. Laws 1849, ch. 77, secs. 1-6/pp. 47-48
1850
Lost territory St. Croix lost jurisdiction of Overlap Area 3 to La Pointe (now Bayfield); both counties had claimed the area since 8 March 1849; Overlap Area 3 eliminated.
to La Pointeto Bayfield
1 January 1850 · Wis. Rev. Stat. 1849, ch. 2, secs. 2, 24, 26/pp. 51, 56-57 and ch. 157, sec. 1/p. 747

Show all 12 changes (7 more)

1840
St. Croix County created St. Croix created by Wisconsin Territory from Crawford and Non-County Area 1 attached to Crawford; St. Croix included territory in present Wisconsin and Minnesota.
from Crawford
3 August 1840 · Wis. Terr. Laws 1839-1840, no. 20, sec. 1/pp. 25-26
1841
Gained territory St. Croix gained small part of Non-County Area 1, lost to Portage.
from Portage
18 February 1841 · Wis. Terr. Laws 1840-1841, no. 38, secs. 1-3, 12/pp. 73-75
1843
Changed St. Croix attached to Crawford "for judicial purposes."
Crawford
10 April 1843 · Wis. Terr. Laws 1842-1843, pp. 56-57
1845
Lost territory St. Croix lost to creation of La Pointe (now Bayfield).
to La Pointeto Bayfield
19 February 1845 · Wis. Terr. Laws 1845, pp. 52-53
1848
Lost territory St. Croix lost territory when the state of Wisconsin was created from Wisconsin Territory; St. Croix eliminated from present Minnesota. St. Croix became a county in the state of Wisconsin. 29 May 1848 · U.S. Stat., vol. 9, ch. 89 [1846]/pp. 56-58, and ch. 50 [1848]/pp. 233-235; Van Zandt, 128, 130
1849
Exchanged territory St. Croix exchanged with Chippewa, gained from La Pointe (now Bayfield). An overlap (Overlap Area 3) was created between St. Croix and La Pointe when both counties were assigned the same area.
with Chippewa with La Pointewith Bayfield
8 March 1849 · Wis. Laws 1849, ch. 77, secs. 1-6/pp. 47-48
1849
Changed St. Croix fully organized, detached from Crawford; La Pointe (now Bayfield) detached from Crawford, attached to St. Croix "for judicial purposes."
Crawford La PointeBayfield
1 April 1849 · Wis. Laws 1849, ch. 53, secs. 1, 3/p. 31; Wis. Laws 1847, pp. 147-148
1850
Lost territory St. Croix lost jurisdiction of Overlap Area 3 to La Pointe (now Bayfield); both counties had claimed the area since 8 March 1849; Overlap Area 3 eliminated.
to La Pointeto Bayfield
1 January 1850 · Wis. Rev. Stat. 1849, ch. 2, secs. 2, 24, 26/pp. 51, 56-57 and ch. 157, sec. 1/p. 747
1850
Changed La Pointe (now Bayfield) fully organized, detached from St. Croix.
La PointeBayfield
1 July 1850 · Wis. Laws 1850, ch. 156, secs. 1-2/p. 126
1853
Lost territory St. Croix lost to creation of Pierce and Polk; Pierce and Polk not fully organized, both attached to St. Croix "for judicial purposes."
to Pierce to Polk
14 March 1853 · Wis. Laws 1853, gen., ch. 31, secs. 1-2, 6/pp. 28-30
1853
Changed Pierce and Polk fully organized, detached from St. Croix.
Pierce Polk
25 November 1853 · Wis. Laws 1853, gen., ch. 31, secs. 1-2, 4-6/pp. 28-29
1943
Lost territory St. Croix lost small area to Pierce in section 36, township 28 north, range 19 west; and section 31, township 28 north, range 18 west.
to Pierce
1 May 1943 · Wis. Laws 1943, ch. 13, secs. 1, 5, 7/pp. 15, 18

Land and parcels

What the maps cover in St. Croix

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

Parcels Good enough

Lot lines and tax-map numbers for 54,897 parcels from St. Croix County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 17 August 2026 · checked 16 October 2026
Address points Missing

No public address points layer found for St. Croix 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

St. Croix by the Census

Population

93,536 2020 Census count

Housing units

37,369 2020 Census count

Land area

722 square miles

Water area

13 square miles

People per sq mi

130 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

Clerk of court: deeds and platsfrom sccwi.gov · checked 13 October 2026

Permits

Health department: septic and wellfrom sccwi.gov · checked 13 October 2026
Child Labor Permit Informationfrom sccwi.gov
Land Use Permit Application (PDF)from sccwi.gov
Sanitary / Septic Informationfrom sccwi.gov

Zoning and code

Land Use and Development Ordinancesfrom sccwi.gov
Land Use and Zoningfrom sccwi.gov
Land Use and Zoningfrom sccwi.gov

County government

County government
The official website of St. Croix County.
sccwi.gov

See your own lot on these maps

Open St. Croix 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 St. Croix County

When was St. Croix County founded?: St. Croix County was founded in 1840, formed from Crawford County.
What is the county seat of St. Croix County?: The county seat of St. Croix County is Hudson.
Is there an online parcel map for St. Croix County?: Yes. St. Croix County publishes a parcel map of 54,897 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has St. Croix County's boundary or name changed?: St. Croix County was created in 1840 from Crawford County. Since then the Atlas of Historical County Boundaries records 11 later changes, chiefly involving Bayfield County, La Pointe County and Pierce County.
Who issues building permits in St. Croix County?: The county's page on building permits: Child Labor Permit Information. Inside a city or town, ask that city first.
Who issues septic and well permits in St. Croix 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 St. Croix County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby