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Missouri County
St. Clair County, Missouri
Order No. 11 and Harry S. Truman Reservoir - from Osceola's Civil War devastation under Order No. 11 (in 1863, Union General Thomas Ewing issued Order No. 11 requiring depopulation of much of west Missouri to suppress guerrilla activity - Osceola was burned and its residents expelled in one of the most controversial acts of the Civil War's western theater, an event that drove many displaced Missourians toward the Confederate cause) to Harry S. Truman Reservoir (the massive 55,600-acre lake along St. Clair County's eastern edge is Missouri's largest lake by surface area, providing exceptional bass fishing, sailing, and water recreation).
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Office: St. Clair County Emergency Management Agency – 655 2nd St., Courthouse, 1st Fl, PO Box 523, Osceola, MO 64776 | (417) 646-2419
Sheriff: St. Clair County Sheriff’s Office – Osceola, MO 64776 | Non-emergency (660) 417-646-2522 / (417) 646-2522
Notes: For an active emergency, call 911.
Roads & Utilities
ROADS & TRANSPORTATION
Roads: MO-13 serves Osceola, the county seat, in west-central Missouri; MO-82 also serves the county near the Harry S. Truman Reservoir.
Notes: St. Clair County, organized January 29, 1841, is named for General Arthur St. Clair of the Revolutionary War, spans 702 square miles, and is part of the Osage River basin where the Ozarks meet the Great Plains.
Business & Permits
BUILDING & PERMITS
Office: St. Clair County Courthouse – Osceola, MO 64776; confirm current building/zoning permit contact via stclaircomo.com.
Notes: Osceola holds a genuinely significant and difficult piece of Civil War history. On September 23, 1861, Kansas Senator and Union General James H. Lane led roughly 1,500-2,000 “Jayhawker” volunteers in an unauthorized raid on the town, then a prosperous Osage River port of around 2,500-3,000 residents. After overwhelming a smaller Missouri State Guard detachment, Lane’s men looted and burned nearly the entire town – of roughly 800 buildings, only three survived – and killed several local men. The raid became one of the most notorious episodes of the Missouri-Kansas border war; two years later, Confederate guerrilla William Clarke Quantrill’s men reportedly cried “Remember Osceola!” during their devastating 1863 raid on Lawrence, Kansas. A monument in the Osceola cemetery commemorates the citizens killed. This history remains a point of local memory today, care taken given its sensitivity.
Veterans Services
VETERANS SERVICES
Office: St. Clair County Veterans Service – confirm current contact via stclaircomo.com.
Libraries
LIBRARIES
System: St. Clair County Library – Osceola, MO 64776, (417) 646-2214; also a branch in Lowry City, MO, and a bookmobile serving the county.
Parks & Recreation
PARKS & RECREATION
Key Assets: St. Clair County offers extensive outdoor recreation along the Harry S. Truman Reservoir (Truman Lake), a 55,600-acre U.S. Army Corps of Engineers flood-control reservoir on the Osage River shared with Henry, Benton, and Hickory Counties, popular for fishing, boating, hiking, and camping. The county is also home to the Shawnee Mound archaeological site, preserving ancient Native American artifacts, and hosts annual events including the St. Clair County Fair and Osceola Heritage Days
Notes: The Truman Reservoir’s shoreline and the county’s Osage River heritage – including the sobering history of the 1861 sacking of Osceola – are genuine and distinctive local features.
GIS & Maps
GIS & MAPS
Appraisal/Parcel Search: St. Clair County Assessor – confirm current contact via stclaircomo.com.
Animal Services
ANIMAL SERVICES
Facility: Helen M. Johnson Memorial Animal Shelter – Osceola, MO 64776
Services: A 501(c)3 nonprofit shelter partnered with and located within the Osceola Vet Clinic, providing rescue, care, shelter, and adoption for homeless dogs in the St. Clair County area, along with education on spay/neuter and humane treatment.
Environmental & Waste
ENVIRONMENTAL / WASTE MANAGEMENT
Office: St. Clair County – confirm current contact via stclaircomo.com.
NOTES
The 1861 sacking of Osceola – one of the most notorious episodes of the Missouri-Kansas border war, later invoked during Quantrill’s raid on Lawrence – is a genuine, well-documented, and sensitive piece of Civil War history tied directly to this county. All contact information above was sourced via web search as of mid-August 2026 and should be reconfirmed directly with the relevant office before a visit, deadline-sensitive filing, or emergency-adjacent decision.
About St. Clair County
St. Clair County is west-central Missouri’s Order No. 11 Civil War heritage and Truman Reservoir county – the Civil War burning of Osceola and Missouri’s largest lake define a county whose dramatic historical scar and recreational asset anchor the community between the Kansas City metro and the Springfield Ozarks.
Osceola (the county seat, population ~880) is St. Clair County’s governmental hub on Truman Reservoir, a west Missouri town whose Civil War history and lake access define its community character.
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St. Clair County Assessor at 655 2nd Street, Osceola, MO 64776, phone 417-646-2211. MO assessed at percentage of true value.
Courts & Legal
St. Clair County Circuit Court at 655 2nd Street, Osceola, MO 64776, phone 417-646-2211, handles probate.
Marriage & Vital Records
Marriage licenses, divorce records, and birth & death certificates are handled by the following office(s):
COUNTY CLERK
655 2nd St., Osceola, MO 64776
(417) 646-2315
Genealogy
County-level record sources
St. Clair County Circuit Court, Probate Division (probate case files – see Probate section above).
Local societies
No dedicated St. Clair 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
St. Clair County Circuit Court, Probate Division 655 Second Street (mail: P.O. Box 493), Osceola, MO 64776 (417) 646-2226 St. Clair County is in west-central Missouri, seated in Osceola.
Step 1: figure out which path applies
Missouri probate is governed by Title XXXI of the Missouri Revised Statutes (Chapters 470-475), the Probate Code.
Small Estate Affidavit (RSMo § 473.097) – available when the entire estate, less liens and encumbrances, does not exceed $40,000. A 30-day waiting period after death applies, and only if no application for letters is pending. If the property listed is worth more than $15,000, the clerk must publish a notice to creditors in a newspaper of general circulation in the county. A bond may be required. Once the court issues a certified small estate certificate, the affiant presents it directly to whoever holds the property to collect and distribute assets – avoiding full probate. Typical timeline: about two months to close, versus six months to a year or more for full probate.
Formal Administration – required for larger or more complex estates. A petition for Letters Testamentary (with a will) or Letters of Administration (without one) is filed with the probate division. After review, the court appoints the personal representative and issues the letters. Missouri offers both supervised and independent administration. Missouri requires an attorney to represent the personal representative in both types of administration.
Step 2: filing for formal probate
File a petition with the Probate Division of the Circuit Court in the county where the decedent was domiciled.
The court appoints the personal representative and issues Letters Testamentary or Letters of Administration.
The personal representative publishes a notice to creditors in a newspaper of general circulation in the county, and gives direct notice to known creditors. Creditors have 6 months from the date of first publication to file claims.
Within 30 days of appointment (unless the court extends the deadline), the personal representative files an inventory and appraisement of all estate assets.
After debts are paid and the creditor claim period expires, the personal representative distributes the remaining assets and files a final settlement with the court to close the estate.
What it costs
Missouri sets statutory minimum fees for attorneys and personal representatives based on a percentage of the estate’s value, though additional fees may be allowed for extraordinary services.
Missouri has no state estate tax and no state inheritance tax. Only the federal estate tax could apply, and only to very large estates.
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
655 2nd St., Osceola, MO 64776
(417) 646-2212
Elections & Voting
Voter registration, polling locations, and elections information are handled by the following office(s):
ELECTIONS
655 2nd St., Osceola, MO 64776
(417) 646-2315
Health & Human Services
Offices & Contacts
Health services, social services, and assistance programs are handled by the following office(s):
MO Dept of Social Services — St. Clair
(417) 646-8122
Golden Valley Memorial Healthcare
gvmh.org (Clinton — accessible)
Public Health Information
PUBLIC HEALTH
Office: St. Clair County Health Department – Osceola, MO 64776, (417) 646-8332.
Hospital: Confirm current nearest hospital via stclaircomo.com; residents commonly access care through nearby regional hospitals in Clinton or Nevada, MO.
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Last verified June 2026
County Facts
County Seat: Osceola
Population: 9,500
Area: 673 sq mi
Established: 1841
Tier: 3
Public Records
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