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Ohio County
Mercer County, Ohio
Grand Lake St. Marys and Ohio's Catholic heartland - from Grand Lake St. Marys (the largest inland lake in Ohio at 13,500 acres, constructed between 1837-1845 as a feeder reservoir for the Miami-Erie Canal - one of the largest artificial lakes in the world at the time of its construction) to Mercer County's distinction as one of Ohio's most devoutly Catholic communities (German Catholic immigrant settlers established parishes, schools, and religious communities throughout the county, creating a cultural character more similar to rural Bavaria than typical Ohio) and the county's exceptional dairy and hog farming productivity.
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Office: Mercer County Emergency Management Agency – confirm current phone via mercercountyohio.gov; mail forms to the Mercer County Auditor’s Office, 101 N Main St, Rm. 105, Celina, OH 45822.
EMS: Mercer County EMS – 321 Riley St., Celina, OH 45822; a 911-based organization serving roughly 41,000 residents across 473 square miles with 110 paid/volunteer paramedics and EMTs operating out of 4 stations with 10 Advanced Life Support ambulances, responding to about 2,600 calls annually.
Public Health After-Hours: Mercer County Health District – (419) 771-6708.
Notes: For an active emergency, call 911.
Roads & Utilities
ROADS & TRANSPORTATION
Roads: US-127 and SR-29/703 serve Celina, the county seat, in west-central Ohio near the Indiana border
Transit: No dedicated county-wide public transit system was found in this search – confirm directly with the county or your city
Notes: Mercer County sits roughly 80 miles west of Columbus.
Business & Permits
BUILDING & PERMITS
Office: Mercer County Building/Permits – confirm current contact via mercercountyohio.gov.
Notes: Mercer County is genuinely home to Grand Lake St. Marys, one of the most historically remarkable engineering feats in Ohio history. Built between 1837 and 1845 entirely by manual labor – roughly 1,700 German and Irish immigrant laborers using only shovels, axes, and mule-drawn sleds – the reservoir was constructed as a feeder for the Miami and Erie Canal and, at 17,500 acres upon completion, was the largest artificial (man-made) lake in the world at the time. It remains today the largest lake in the world built entirely without machinery, and Ohio’s largest inland lake at roughly 13,500 acres (straddling Mercer and Auglaize counties). Workers were paid about 30 cents a day plus a daily ration of whiskey, believed at the time to ward off malaria from the swampy work site. The lake was originally known as Lake Mercer or the Mercer Reservoir; St. Marys itself was the original county seat of Mercer County before Auglaize County was carved out in 1848. Remarkably, Grand Lake St. Marys was also the site of the world’s first offshore oil well drilling, in 1891, with derricks built on platforms across the lake.
Veterans Services
VETERANS SERVICES
Office: Mercer County Veterans Service Commission – 220 W. Livingston St., Room 2701/B270, Celina, OH 45822 | (419) 586-3542 | Fax: (419) 586-7702 | Hours: Mon-Fri 8 AM-4:30 PM (appointments helpful but not required); Director/CVSO Eric Pugh; Board meets 4th Tuesday of the month at 9 AM; provides temporary financial assistance for veterans, dependents, or widows on a case-by-case basis (90-day county residency required).
State: Ohio Department of Veterans Services – dvs.ohio.gov
Libraries
LIBRARIES
System: Mercer County District Library – Celina Main Library, 303 N Main St, Celina, OH 45822 | (419) 586-4442 | Fax: (419) 586-3222 | [email protected] | Hours: Mon-Fri 9 AM-8 PM, Sat 9 AM-5 PM, closed Sunday.
Parks & Recreation
PARKS & RECREATION
Key Assets: Grand Lake St. Marys State Park (see above) is the county’s premier, historically remarkable attraction, offering boating, fishing, swimming, and camping across 52 miles of shoreline.
Notes: The genuine “world’s largest hand-built artificial lake” heritage of Grand Lake St. Marys is one of the most distinctive engineering-history facts covered anywhere in this project.
GIS & Maps
GIS & MAPS
Appraisal/Parcel Search: Mercer County Auditor – 101 N Main St, Rm. 105, Celina, OH 45822.
Animal Services
ANIMAL SERVICES
Facility: Mercer County Dog Warden – 7009 State Route 49, Celina, OH 45822 | (419) 942-1550; Chief Dog Warden Thomas Powell.
Environmental & Waste
ENVIRONMENTAL / WASTE MANAGEMENT
Office: Mercer County Solid Waste – confirm current contact via mercercountyohio.gov.
NOTES: Mercer County is the fifth county in this batch (Mahoning, Marion, Medina, Meigs, Mercer, Miami, Monroe) of the Ohio v2 redo. The genuine “world’s largest hand-built artificial lake” heritage of Grand Lake St. Marys is one of the most distinctive engineering-history facts covered anywhere in this project. All contact information above was sourced via web search as of early August 2026 and should be reconfirmed directly with the relevant office before a visit, deadline-sensitive filing, or emergency-adjacent decision.
About Mercer County
Mercer County is west-central Ohio’s most distinctively Catholic agricultural county – a community of German immigrant heritage where church steeples define the landscape and Grand Lake St. Marys provides recreation on Ohio’s largest inland lake.
Celina (the county seat, population ~10,000) sits on the shore of Grand Lake St. Marys – a reservoir constructed as a canal feeder but evolved into one of Ohio’s premier recreational lakes. Boating, fishing, and lakeshore development support a significant tourism economy.
Mercer County’s German Catholic heritage is expressed in the density and quality of its parish churches – St. Henry, Coldwater, Fort Recovery, and numerous other small communities maintain active Catholic parishes, parochial schools, and the social fabric of German-American Catholic rural life.
The county’s agricultural productivity – particularly dairy and hog production – ranks among Ohio’s highest, reflecting the German immigrant tradition of intensive, careful farm management.
All Services
Browse every category and topic available for this county.
Mercer County Auditor at 101 N. Main Street, Suite 103, Celina, OH 45822, phone 419-586-2259. Appeal to County Board of Revision by April 1.
Courts & Legal
Mercer County Probate Court at 101 N. Main Street, Room 203, Celina, OH 45822, phone 419-586-7458, handles probate.
Marriage & Vital Records
Marriage licenses, divorce records, and birth & death certificates are handled by the following office(s):
PROBATE COURT
101 North Main St, Celina, OH 45822
(419) 586-2601
Genealogy
County-level record sources
Mercer County Probate/Juvenile Court, Celina (probate/estate case files – see Probate section above).
Local societies
No dedicated Mercer 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
Mercer County Probate/Juvenile Court 101 North Main Street, Suite 307, Celina, OH 45822 (419) 586-8779 Mercer County is in western Ohio along the Indiana border, seated in Celina.
Step 1: figure out which path applies
Ohio has not adopted the Uniform Probate Code, but has incorporated some streamlined concepts into its own system under Title 21 of the Ohio Revised Code (ORC Chapters 2101-2131).
Summary Release from Administration (ORC § 2113.03) – available for very small estates valued at $5,000 or less. Lets the court release assets quickly, often to cover funeral expenses and support the surviving family, without a fiduciary being appointed.
Release from Administration (ORC § 2113.03) – Ohio’s broader small-estate shortcut. Available when the gross probate estate is $35,000 or less, OR up to $100,000 if the entire estate passes to a surviving spouse (by will or by Ohio’s intestacy law). No executor/administrator is appointed; the court releases the estate directly to the person(s) entitled to it.
Full Estate Administration – required when the estate exceeds these thresholds or the situation is otherwise contested or complex. The court appoints a fiduciary (Ohio’s term for executor/administrator), issues a Certificate of Appointment once any will is admitted, and the fiduciary inventories assets, publishes notice to creditors, pays debts, and distributes what remains under ongoing court supervision.
Step 2: filing for administration
File the will (if any) and an application with the Probate Court in the county where the decedent resided.
If pursuing Release from Administration or Summary Release, complete the applicable court forms (Form 5.0 for standard Release, Form 5.10 for Summary Release) along with a complete asset inventory and supporting documents.
For full administration, the court issues Letters Testamentary or Letters of Administration to the appointed fiduciary.
The fiduciary publishes notice to creditors; claims generally must be presented within 6 months of the date of death.
The fiduciary inventories and manages estate assets, pays valid debts and expenses, and distributes what remains according to the will or Ohio’s intestacy law, reporting to the court along the way.
The estate is closed once a final account is filed and approved by the court.
What it costs
Filing fees vary by county – check with Mercer County directly for current fees.
No state estate tax, no state inheritance tax (repealed effective January 1, 2013). Only the federal estate tax could apply, and only to very large estates ($15,000,000 per individual as of 2026).
Probate filings, estate administration, and guardianship matters are handled by the following office(s):
PROBATE COURT
101 North Main St, Celina, OH 45822
(419) 586-2601
Public Safety & Arrests
Arrest records, inmate search, and law enforcement services are handled by the following office(s):
SHERIFF
4949 State Route 29, Celina, OH 45822
(419) 586-7724
Elections & Voting
Voter registration, polling locations, and elections information are handled by the following office(s):
BOARD OF ELECTIONS
4900 Wagner Ave, Celina, OH 45822
(419) 586-6969
Health & Human Services
Offices & Contacts
Health services, social services, and assistance programs are handled by the following office(s):
Health Department
220 West Livingston St, Celina, OH 45822
(419) 586-6427
Job and Family Services
220 West Livingston St, Celina, OH 45822
(419) 586-6116
Public Health Information
PUBLIC HEALTH
Office: Mercer County Health District – 220 W. Livingston Street, Suite B152, Celina, OH 45822.
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Last verified June 2026
County Facts
County Seat: Celina
Population: 41,000
Established: 1820
Tier: 3
Public Records
TruthFinder
Search public records for Mercer County residents.
