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Wisconsin · Fox River Valley · #437
Winnebago County, Wisconsin
On the western shore of Lake Winnebago - the largest inland lake in Wisconsin - Winnebago County hosts the world's largest airshow in Oshkosh and a paper-and-manufacturing economy that has kept the Fox River Valley among Wisconsin's most productive industrial corridors for 150 years.
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Office: Winnebago County Emergency Management – Oshkosh, WI 54901
Services: County-level emergency planning and coordination; the county was among those approved for FEMA disaster Individual Assistance following April 2026 severe storms, tornadoes, and flooding.
Notes: Winnebago County Sheriff’s Office non-emergency line, (920) 236-7300, handles fire non-emergency reporting.
Roads & Utilities
ROADS & TRANSPORTATION
Roads: US-41, WI-21, and WI-44 serve Oshkosh, the county seat
Airport: Wittman Regional Airport in Oshkosh becomes, for one week each summer during EAA AirVenture, the busiest airport control tower in the world.
Transit: GO Transit provides local bus service in the Oshkosh area.
Business & Permits
BUILDING & PERMITS
Office: Winnebago County Zoning Office – (920) 232-3344
Services: Retains jurisdiction over NR 115 shoreland zoning (within 1,000 feet of navigable waters) even in incorporated towns; also handles erosion control and stormwater permits countywide. Individual towns and municipalities issue their own general building permits – confirm with your local Town Building Permit Administrator.
Veterans Services
VETERANS SERVICES
County VSO: Winnebago County Veterans Service Office – Oshkosh, WI 54901
Libraries
LIBRARIES
System: Oshkosh Public Library – Oshkosh, WI 54901
Parks & Recreation
PARKS & RECREATION
Key Assets: Winnebago County is genuinely home to EAA AirVenture Oshkosh, the world’s largest fly-in and general aviation gathering, held every summer at Wittman Regional Airport. Founded by the Experimental Aircraft Association in 1953, the week-long event draws nearly 700,000 attendees and more than 10,000 aircraft from around the world, and the EAA Aviation Museum, with over 200 aircraft, is open year-round. The county also contains the majority of Lake Winnebago, Wisconsin’s largest inland lake at roughly 137,700 acres – about 30 miles by 10 miles with 88 miles of shoreline – offering walleye and northern pike fishing, boating, and winter ice fishing. Oshkosh is also home to the Paine Art Center and Gardens and the 1937 Winnebago County Courthouse, an Art Deco/Moderne landmark on the National Register of Historic Places, notable for its Mayan Revival bas-relief sculptures by Alfonso Ianelli
Notes: EAA AirVenture Oshkosh is genuinely the world’s largest fly-in and aviation gathering, and Winnebago County contains the largest inland lake in Wisconsin.
GIS & Maps
GIS & MAPS
GIS Portal: Winnebago County GIS – accessible via winnebagocountywi.gov
Parcel Search: Winnebago County Assessor – Oshkosh, WI 54901
Addressing/911: Coordinated through Winnebago County Emergency Management
Animal Services
ANIMAL SERVICES
Facility: Oshkosh Area Humane Society – 1925 Shelter Ct, Oshkosh, WI 54901 | (920) 424-2128 | Public Visiting Hours: Tue-Fri 1-6 PM, Sat 11 AM-3 PM
Services: A nonprofit shelter helping more than 3,200 animals annually, offering adoption, community outreach, and pet-owner support services; scheduled appointments required to meet dogs due to space/staff constraints.
Notes: Lake Winnebago and Fox River watershed management, and stormwater/erosion control across the county’s shoreland zoning jurisdiction, are significant local environmental focus areas.
NOTES
EAA AirVenture Oshkosh is genuinely the world’s largest fly-in and aviation gathering, and Winnebago County contains the largest inland lake in Wisconsin. All contact information above was sourced from official county, city, library, and shelter pages as of this writing; phone numbers and hours should be reconfirmed directly with the relevant office before a visit.
About Winnebago County
Winnebago County’s most globally known event happens every July when Oshkosh hosts EAA AirVenture – the Experimental Aircraft Association’s annual fly-in convention that draws more than 600,000 visitors and transforms Wittman Regional Airport into the busiest airport in the world for one week. The event’s combination of aviation history, homebuilt aircraft, military flight demonstrations, and airshow performances has made Oshkosh synonymous with aviation enthusiasm worldwide. The EAA Museum, open year-round, maintains one of the finest collections of historic aircraft in the country.
Beyond AirVenture, Winnebago County is a Fox River Valley manufacturing county. Oshkosh Corporation – maker of specialized vehicles including military trucks (the M-ATV), airport firefighting equipment, and work vehicles – is headquartered in Oshkosh and is the county’s largest employer. Neenah, on the county’s northern border, shares the Fox Cities metro with Menasha and has historically been associated with the paper industry (Neenah Paper, Kimberly-Clark’s origins). Lake Winnebago provides one of Wisconsin’s most productive fishing environments – the sturgeon spearing season in February is a Wisconsin tradition of remarkable scale, with 10,000 participants waiting for the state’s ice-fishing season to open on the ice-covered lake. University of Wisconsin-Oshkosh contributes educational and cultural programming. The county’s combination of industrial strength, lake recreation, and AirVenture’s global reach makes it more substantial than its population suggests.
All Services
Browse every category and topic available for this county.
Wisconsin assesses property at 100% of fair market value at the municipal level, with annual assessments by city, village, and township assessors. Property owners may appeal to the local Board of Review. The Homestead Credit provides income-based property tax relief. Wisconsin has an estate tax on estates above $5 million; no Wisconsin inheritance tax.
Courts & Legal
Courts & Legal
SENIOR SERVICES
Aging and Disability Resource Center of Winnebago County
415 Jackson Street, Oshkosh, WI 54901
Phone: (920) 232-3640
Senior transportation, Meals on Wheels, caregiver support, ADRC counseling, home modification, and long-term care options for Winnebago County residents.
Senior Services
Aging and Disability Resource Center of Winnebago County
415 Jackson Street, Oshkosh, WI 54901
Phone: (920) 232-3640
Senior transportation, Meals on Wheels, caregiver support, ADRC counseling, home modification, and long-term care options for Winnebago County residents.
Marriage & Vital Records
Marriage licenses, divorce records, and birth & death certificates are handled by the following office(s):
COUNTY CLERK
415 Jackson St, Oshkosh, WI 54901
(920) 236-4885
Genealogy
County-level record sources
Winnebago County Register in Probate, Oshkosh (probate/estate case files – see Probate section above). The Winnebago County Courthouse (1937, Moderne/Art Deco, designed by Frank Venning and Granger & Bollenbacher) is on the National Register of Historic Places, notable statewide as an example of Moderne architecture.
Local societies
No dedicated Winnebago County genealogical society was confirmed in available directories.
Probate & Estate
Losing someone and having to deal with courts and paperwork at the same time is hard. This section won’t make that easier, but it should tell you what to expect, what it costs, and where to go – so at least you’re not walking in blind.
Where to go
Winnebago County Register in Probate 415 Jackson Street, Room 242, PO Box 2808, Oshkosh, WI 54903 (920) 236-4833
Winnebago County was created in 1848, named for the Winnebago people (Ho-Chunk Nation), home to Oshkosh and Neenah, county seat Oshkosh. Wisconsin has NOT adopted the Uniform Probate Code and has NO separate probate court – probate is handled by the CIRCUIT COURT (Probate Division) for the county where the decedent lived, administered day-to-day by that county’s REGISTER IN PROBATE, whose office also oversees files for guardianships, mental/alcohol/drug commitments, terminations of parental rights, and adoptions. Wisconsin runs two main tracks: FORMAL administration, supervised directly by a circuit court judge, and INFORMAL administration, supervised by the Register in Probate without continuous judicial oversight. Informal administration is the default path for most straightforward estates.
Step 1: figure out which path applies
Wisconsin Statutes Chapters 851 through 882 govern probate. Wisconsin is also a MARITAL PROPERTY state (similar to community property) – under the Wisconsin Marital Property Act, most assets acquired during marriage are co-owned by both spouses, so a surviving spouse may already own half of all marital property outright; only the decedent’s half passes through the estate.
Transfer by Affidavit (Form PR-1831, per Wis. Stat. §867.03) – available when the decedent’s ENTIRE probate estate (personal property only; real estate is not covered by this shortcut) has a gross value of $50,000 or less. Available 30 days after death to an heir, a trustee of a revocable trust, a beneficiary named in the will, or a guardian of the decedent.
Survivorship – jointly held assets or those with beneficiary designations (POD/TOD) pass directly to the survivor without probate.
Summary Settlement (Wis. Stat. §867.01) – geared toward estates of $50,000 or less where there is a surviving spouse, domestic partner, or minor children, or where the estate would otherwise be absorbed by allowances and expenses.
Summary Assignment – another shortcut for estates too small to pay debts in full.
Formal or Informal Administration – required for larger or more complex estates. Begins with a Petition for Administration (Form PR-1801) filed with the county Register in Probate to admit the will (if any) and appoint a personal representative.
Step 2: filing for administration
File a Petition for Administration (Form PR-1801) with the Winnebago County Register in Probate.
Mail notice of the hearing to all heirs, beneficiaries, and interested parties at least 20 days before the hearing; publish notice in a newspaper of general circulation in the county for three successive weeks.
Once appointed, the personal representative inventories assets, and the court (for formal administration) or Register in Probate (for informal) sets a creditor claims deadline – generally 3 to 4 months from the date of the court’s order, with first publication of that notice required within 15 days of the order.
The personal representative pays valid debts and expenses, then distributes remaining assets to heirs/beneficiaries.
File a final accounting with the Circuit Court (Probate) showing all assets received, debts paid, and distributions made; once approved, the estate is closed.
Wisconsin’s probate filing fee statewide is generally 0.2% of inventory value, minimum $20.
What it costs
Filing fee: approximately 0.2% of the estate’s inventory value, minimum $20.
Personal representative compensation: presumptive statutory rate of 2% of inventory value (Wis. Stat. §857.05), though the will or the parties can agree to a different amount.
Publication costs, and (for real estate transfers under the small-estate process) an Affidavit of Heirship and Affidavit of Service, notarized and filed with the court.
Typical timeline: simple estates 6-12 months; complex or contested estates 18 months or longer.
Wisconsin does NOT impose a state estate tax or inheritance tax. Only the federal estate tax may apply, with a $15,000,000 per-person exemption for 2026 – meaning the vast majority of Wisconsin estates owe nothing.
Probate filings, estate administration, and guardianship matters are handled by the following office(s):
Public Safety & Arrests
Arrest records, inmate search, and law enforcement services are handled by the following office(s):
SHERIFF
4311 Jackson St, Oshkosh, WI 54901
(920) 236-7300
Elections & Voting
Voter registration, polling locations, and elections information are handled by the following office(s):
ELECTIONS
(920) 236-4885
Health & Human Services
Offices & Contacts
Health services, social services, and assistance programs are handled by the following office(s):
Public Health Department
Winnebago County Public Health Department, 112 Otter Ave, Oshkosh, WI 54901
(920) 232-3000
Human Services
Winnebago County Human Services, 220 Washington Ave, Oshkosh, WI 54901
(920) 232-1400
Public Health Information
PUBLIC HEALTH
Office: Winnebago County Public Health – Oshkosh, WI 54901
Hospital: Ascension Northeast Wisconsin Mercy Hospital (Mercy Medical Center) – Oshkosh, WI, a Level III trauma center open since 1891.
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Last verified June 2026
County Facts
County Seat: Oshkosh
Population: 172,500
Tier: 2
Inmate Services
Care Packages
Send care packages to inmates in Winnebago County facilities via Amazon.
