Colusa County lies on the west side of the Sacramento Valley, between the Sacramento River and the Coast Range foothills. The 2020 Census counted 21,839 residents. The two cities hold more than half of them: Colusa, the county seat, has 6,411 and Williams has 5,538. The rest live in towns such as Arbuckle, Maxwell, Grimes and Princeton, and on ranches.
Valpro Attorney Services handles Colusa County process serving, court filings and document retrieval out of our Sacramento office. Upload papers through a Service Request, or email them to Service@ValproAttorneyServices.com.
Two buildings in downtown Colusa
Colusa Superior Court lists two locations, both in the city of Colusa, and only one of them takes filings.
Courthouse Annex, Department 2, 532 Oak Street. This is where the Clerk's Office is. The court's criminal pages send people to the Clerk's Office at 532 Oak Street, and the e-filing, family law and small claims pages refer filers to the Clerk's Office. It is the only clerk's office the court names.
Main Courthouse, Department 1, 547 Market Street. The Main Courthouse holds the Department 1 courtroom and the Self-Help Center. Hearings are held here, but filing happens at Oak Street.
Both location pages list building hours of 8:30 a.m. to 5:00 p.m., Monday through Friday. The court's main number is (530) 458-5149.
E-filing now, and the rule proposed for 2027
Today, e-filing in Colusa is optional. The court's e-filing page says it is permissive for initial and subsequent filings in all civil cases (limited and unlimited), probate, family law and juvenile dependency, and for subsequent filings only in criminal and traffic cases. Its FAQ answers the obvious question directly: e-filing is permissive and not required for all litigants, and you can file by mail or in person at the Clerk's Office.
That may change. On September 30, 2026, the court posted proposed amendments to its local rules, to take effect January 1, 2027. Proposed Rule 1.17 would make e-filing and e-service mandatory in all civil, probate, family law and juvenile dependency cases. Self-represented litigants and non-parties would be exempt. Subsequent filings in criminal, traffic and juvenile delinquency cases would stay permissive. Written comments are due by 5:00 p.m. on Friday, November 13, 2026.
Until the court adopts it, Rule 1.17 is only a proposal. We'll file Colusa papers either way through our Court Filings service, on paper at Oak Street or through an approved provider. The Court Filings page explains what to send. General information, not legal advice.
The Sheriff's Civil Unit, next to the clerk
The Colusa County Sheriff's Civil Unit lists the same physical address as the Clerk's Office: 532 Oak Street. Its office is open 8:30 a.m. to 4 p.m. on weekdays, and its page notes that most service requests made after 4:00 p.m. aren't processed until the next business day. Field deputies may serve previously processed requests on any day, including evenings.
A private server is the alternative. Anyone at least 18 who isn't a party can serve, and paid servers who serve more than 10 papers a year register with a county clerk. Our guide on who can serve papers in California covers the rules, and the proof of service guide explains how service is documented.
Close to Sacramento, with a few far corners
Colusa County is close by our standards. The city of Colusa is about 50 miles straight-line from our office, and Williams about 51.
I-5 towns. Williams, Arbuckle and Maxwell are on or just off the freeway, which makes them quick to reach.
River towns. Colusa, Grimes, Princeton and College City are near the Sacramento River and State Route 45, among levees and farm roads.
The western foothills. Stonyford, Lodoga and the ranch country toward the Mendocino National Forest are on long county roads west of I-5.
Remote areas are subject to different timelines. For a foothill address, we confirm timing before you choose Rush.
What to include for a rural address
Ranch and orchard properties can sit far back from the road. Help the server with:
- the physical address, not a rural route or P.O. box
- the driveway, gate or shop building where the person can be found
- the person's employer and work hours
- a description of the vehicle, if known
- any other address in Yolo, Glenn, Sutter or Lake County
When an address doesn't hold up, skip tracing can search for a current one. Our post on how to find a defendant in California describes how.
Evictions, businesses and AB 747
Colusa evictions are filed at the Oak Street Clerk's Office. After personal service, the tenant's answer is due within 10 court days. For a company, service usually goes to its agent for service of process; see serving corporations.
On January 1, 2027, AB 747 takes effect. Three good-faith attempts on 3 different days at 3 different times show reasonable diligence for substituted service under CCP § 415.20(b)(2), and the county clerk's register of process servers becomes public under Bus. & Prof. Code § 22355. Our AB 747 guide explains more. General information, not legal advice.
Start Colusa County service
Start a Service Request, upload up to 5 PDFs, and select Rush or Standard. Reply to your confirmation email any time for an update. Call 855-582-5776 Monday through Friday, 8:30 a.m. to 5 p.m.
Neighboring counties: Yolo County, Glenn County, Sutter County and Lake County.