Duncans Mills, CA Real Estate & Homes for Sale
By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.
Duncans Mills is a small unincorporated village on Highway 116 on the lower Russian River in west Sonoma County, California, inside the county’s Coastal Zone and designated a County Historic District. So few homes trade here that public sources don’t support a usable median; nearby Monte Rio’s was $475,000 for the three months ending August 2026 (Redfin). Buying here means working through coastal permits, river flooding and private utilities.
- County
- Sonoma County
- Government
- Unincorporated (Permit Sonoma)
- ZIP code
- 95430
- Planning overlays
- Coastal Zone; County Historic District
- Sales data
- Too few sales for a median
- Highway 116
- Closes west of the village at 39 ft on the river gauge (NWS)
Duncans Mills homes for sale
Any current Duncans Mills listings appear below. Because a listing here can be months apart, we usually set buyers up with a saved search on our property search that also covers Monte Rio, Jenner and Cazadero.
What do homes in Duncans Mills sell for?
$475,000
3 months to August 2026, Redfin
$1.2 million
3 months to June 2026, Redfin
$875,000
September 2026, C.A.R.
There isn’t an honest Duncans Mills price figure to give. Redfin’s page for ZIP 95430 showed two sales in its latest window and hadn’t been updated for 2026, and the Census Bureau’s survey for the ZIP is too small to estimate population or home values. The two towns on either side bracket the range instead: river-town prices in Monte Rio and coastal prices in Jenner, where a few sales also swing the median.
| Measure | Figure | Period and source |
|---|---|---|
| Duncans Mills (ZIP 95430) sales | 2 in Redfin’s latest window; no 2026 figures | Redfin, checked October 2026 |
| ZIP 95430 housing units | 16 (margin ±27), too small to use | 2020–2024 American Community Survey, Census Reporter |
| Monte Rio median sale price | $475,000 | 3 months ending August 2026, Redfin |
| Jenner (ZIP 95450) median sale price | $1.2 million | 3 months ending June 2026, Redfin |
| Sonoma County median | $875,000 | September 2026, C.A.R. |
To value a Duncans Mills property we go back two years or more and look across the lower river, then adjust for flood exposure, water source, coastal-permit history and whether the parcel is residential or part of the commercial strip.
Buying in a Coastal Zone historic village
Duncans Mills began as a railroad depot and commercial center in the 1880s. The county’s Local Coastal Plan describes it as “a County Historic District” whose western false-front commercial buildings have been preserved, with newer buildings of similar design added alongside (Permit Sonoma). Those two designations, coastal and historic, shape what an owner can change.
- The plan in force: the county adopted its updated Local Coastal Plan as certified by the Coastal Commission on February 4, 2025, and is now rewriting the coastal zoning code to match.
- Coastal permits: parcels in the zone carry “CC” in their zoning, and development there needs a coastal permit unless the plan exempts it. Permit Sonoma issues most of them.
- Appeals: the Coastal Commission can hear appeals on work within 300 feet of a beach or bluff edge, or within 100 feet of a wetland, estuary or stream, which can include river-edge parcels (Permit Sonoma LCP FAQ).
- Historic district: before you plan exterior changes, new signs or a rebuild, ask Permit Sonoma what review the historic designation triggers for that parcel.
Only the county’s documentary transfer tax, $1.10 per $1,000, applies at sale.
Flooding and the Highway 116 closure
The Weather Service’s impact list for the Guerneville river gauge names two Duncans Mills thresholds. At 38 feet, Freezeout Road floods at Moscow Road; at 39 feet, Highway 116 closes west of the village (NOAA National Water Prediction Service). Flood stage on that gauge is 32 feet and the flood of record, in February 1986, was 49.5 feet.
In February 2019 the river crested at 45.38 feet late on February 27, more than six feet above the Highway 116 closure level. The county’s after-action report called it the sixth-highest crest on record and the highest since 1995, and it logged “100s of landslides impacting roadways” across the county (Sonoma County Emergency Management). In January 2023, the county’s evacuation warning covered zones along the lower river from Healdsburg to Jenner, with an alert that homes above the 40-foot level could lose road access.
On any Duncans Mills parcel, find out three things before you remove contingencies: the FEMA flood zone, the floor and driveway elevations against the 38- and 39-foot marks, and a flood insurance quote. Standard homeowner’s policies exclude flood.
Water and septic
Permit Sonoma’s water and sewer referral list names districts for Monte Rio, Jenner, Camp Meeker and other west county places, but none for Duncans Mills. The county’s own note is that properties outside those providers “may be on a small well or served by a septic system” (Permit Sonoma). Ask the seller exactly where the water comes from, who owns the system, and for test results.
Septic deserves the same care. A village on the river’s edge sits close to the Russian River’s Advanced Protection Management Program area, by default land within 600 feet of the bank, where every septic system falls in Tier 3: the county’s septic program applies “enhanced standards” there, a higher standard than its regular Tier 2 rules (Permit Sonoma). The county doesn’t require a septic inspection at sale, so order one, with the permit record and the tank and leach-field locations. Our Sonoma County wells and septic guide lists what to ask for.
Vacation rentals in Duncans Mills
Short-term rentals are part of the village. When the county counted transient occupancy tax registrations in the Coastal Zone on May 7, 2021, Duncans Mills had 14, against 33 in Jenner and 205 in Bodega Bay (Sonoma County Board of Supervisors). Permit Sonoma allows vacation rentals with a permit in the Coastal Zone, and an ADU or junior ADU can’t be one.
The coastal rules have been moving. The Coastal Commission staff report on the county’s 2024 coastal rental amendment describes a license requirement, one rental per parcel, occupancy of two per bedroom plus two up to 12 guests, on-site parking, and no neighborhood caps (California Coastal Commission). Confirm which rules are in effect with Permit Sonoma before you buy, and budget for the county’s 12% transient occupancy tax. Our guide to vacation rental rules in Sonoma County covers the permit steps.
Fire, insurance and getting around
Check the parcel’s Fire Hazard Severity Zone on CAL FIRE’s map; the state-area zones took effect April 1, 2024 (Permit Sonoma). If the zone is High or Very High, the AB 38 defensible-space paperwork becomes a closing item. Ask for fire and flood insurance quotes as separate lines in your budget.
Highway 116 runs east through Monte Rio and Guerneville and west to the coast at Jenner. Sonoma County Transit’s Route 20 begins in Monte Rio, and Mendocino Transit Authority’s Route 95 runs seven days a week along the coast through Jenner to Santa Rosa (Sonoma County Transit; MTA). Neither lists a Duncans Mills stop. Sonoma Coast State Park’s beaches run 17 miles from Bodega Head to the Vista Trail north of Jenner, and Armstrong Redwoods, which shares its entrance with Austin Creek State Recreation Area, is about three miles north of Guerneville.
Duncans Mills compared with nearby areas
| Area | What’s different from Duncans Mills |
|---|---|
| Monte Rio | Sweetwater Springs public water; flood levels mapped street by street; enough sales for a median ($475,000, 3 months to August 2026) |
| Jenner | On the coast; platted in 1914 as a second-home development, with water-connection and septic limits on small lots |
| Cazadero | Inland rural parcels outside the public water districts; under 2020 Walbridge Fire evacuation orders |
| Guerneville | Public sewer and water; about 4,100 residents (ACS 2020–2024) |
How Diamond Real Estate Group helps Duncans Mills buyers
With a place this small, the paperwork tells you more than the comparables. We confirm the parcel’s zoning and coastal status, ask Permit Sonoma what the historic district means for your plans, trace the water source and septic permit, and set the floor and road elevations against the river’s 38- and 39-foot marks. If rental income matters, we check the current coastal rental rules before you write an offer.
For the rest of the county, see the Sonoma County real estate guide, our guide to buying a second home in Sonoma County and how we represent buyers.
Selling a home in Duncans Mills
Duncans Mills has no local government, so a seller’s records come from Permit Sonoma: building permits, coastal permits and anything tied to the village’s status as a County Historic District. The flood history usually draws the most questions, so assemble it first.
Flood paperwork
- Elevation certificate. Permit Sonoma may have one on record for the house. If it doesn’t, a civil engineer or licensed land surveyor prepares one, showing the lowest adjacent grade next to the structure.
- Flood zone. The county offers flood zone map determinations on request, and the Natural Hazard Disclosure statement reports any FEMA Zone A or V.
- History. List past floods that reached the lot, the garage or the living space, the repairs made and any permits for them. Note road closures that cut off access.
Our flood zone guide explains what buyers’ lenders and insurers will look at.
Coastal and historic review
Under the county’s coastal plan almost every project counts as development unless it is listed as exempt, and work within 100 feet of a stream can be appealed to the Coastal Commission. Pull the coastal permit for each addition or exterior change. If a past project went through historic district review, include those approvals; if you are unsure whether one applied, ask Permit Sonoma before a buyer does.
Water, septic and rentals
- Water. The county’s referral list names no provider for Duncans Mills. Document the well or shared system, any water-sharing agreement and recent test results.
- Septic. Have the permit, pumping receipts and the system’s location map. Supplemental treatment means an annual Permit Sonoma operating permit, and form WLS-043 commits you to notify the buyer.
- Rentals. A coastal rental license belongs to the owner who holds it, so a buyer needs a new one. Gather your hotel-tax payment history in case it matters for the zoning permit.
Tax and state items
The county transfer tax is $0.55 per $500 with no city layer, or $880 on an $800,000 sale. Sellers customarily cover it in Diamond’s North Bay markets, but buyers and sellers can split it; our California transfer tax guide shows the math. If the parcel is in a High or Very High fire hazard zone, provide recent defensible-space documentation or sign the buyer agreement. Every sale also needs your smoke alarm statement and water heater bracing certification; our Sonoma County selling guide covers the full disclosure set.
For help pricing a home with so few nearby sales, see our seller services.
Sources for this section: Permit Sonoma: Floodplains and floodways; California Public Law: Civil Code section 1103.2 (Natural Hazard Disclosure Statement); Permit Sonoma: Local Coastal Plan frequently asked questions; Permit Sonoma: SAN-006 water and sewer referral list; Permit Sonoma: Operational Permit and Monitoring Program; Permit Sonoma: Form WLS-043, acknowledgement of operational permit requirement; Permit Sonoma: Vacation rental permit and license application; County of Sonoma Clerk-Recorder: Documentary transfer tax; Justia: California Civil Code section 1102.19; Permit Sonoma: Property sales inspections (AB 38); California Public Law: Health and Safety Code section 13113.8; California Public Law: Health and Safety Code section 19211.
Duncans Mills real estate FAQs
Where is Duncans Mills, California?
On Highway 116 on the lower Russian River in west Sonoma County, downriver from Monte Rio and upriver from Jenner. It’s unincorporated, and its ZIP code is 95430.
How much do homes in Duncans Mills cost?
There aren’t enough sales to say. Redfin listed two in its latest window for the ZIP, so we price each property from lower-river sales over a longer period, with Monte Rio ($475,000) and Jenner ($1.2 million) as rough bookends.
Is Duncans Mills in the Coastal Zone?
Yes. The county’s Local Coastal Plan lists it among its coastal communities, and the county counted its vacation rentals with the Coastal Zone’s. Expect coastal permits for most building work.
What does the County Historic District mean for an owner?
The village’s false-front commercial buildings are preserved under the designation, and exterior changes may need extra review. Ask Permit Sonoma what applies to the specific parcel before you plan work.
Does Duncans Mills flood?
Low-lying parts do. The Weather Service expects Freezeout Road at Moscow Road to flood at 38 feet on the Guerneville gauge, and the river reached 45.38 feet in February 2019.
Does Highway 116 close in a flood?
Yes, west of Duncans Mills at 39 feet on the gauge, so a big flood can cut the road to the coast. Plan for staying put during winter storms.
Is there public water or sewer in Duncans Mills?
The county’s referral list names no water or sewer provider for the village, so expect a small well or shared system and septic. Confirm the arrangements for each property.
Can I run a vacation rental in Duncans Mills?
Possibly. The Coastal Zone allows them with a county permit, and Duncans Mills had 14 registered in 2021. Check the current coastal license rules and the property’s septic capacity first.
Do I need a coastal permit to remodel?
Often. Most development in the Coastal Zone needs one unless the plan exempts it, and work near the river can fall in the Coastal Commission’s appeal area.
Is there a bus to Duncans Mills?
Not one that lists a stop here. Sonoma County Transit Route 20 starts in Monte Rio, and Mendocino Transit Authority Route 95 runs through Jenner.
What school district serves Duncans Mills?
Confirm it by address. Neighboring Monte Rio has a K–8 public school, Monte Rio Elementary, run by the Monte Rio Union Elementary district.
Sources & notes
- Permit Sonoma: Local Coastal Plan coastal communities, current Local Coastal Plan, LCP FAQ, water and sewer referral list, septic manual, vacation rentals and fire hazard zones
- NOAA National Water Prediction Service: Russian River at Guerneville; Sonoma County Emergency Management: February 2019 and January 2023 after-action reports
- Sonoma County Board of Supervisors: vacation rental workshop report (July 2021); California Coastal Commission: staff report on the coastal vacation rental amendment (April 2024)
- Redfin: ZIP 95430, Monte Rio and ZIP 95450; Census Reporter: ZIP 95430; C.A.R.: September 2026
- Sonoma County Transit: Route 20; Mendocino Transit Authority: Route 95; California State Parks: Sonoma Coast State Park; CDE: Monte Rio Elementary
Figures carry their dates where they appear, and we refresh market numbers every quarter. This is general information, not legal, tax or insurance advice; confirm the rules for a specific property with the agency named. Last reviewed October 2026 by Matthew Martinez.
Plan your next move
Share your preferred location, budget, property requirements and timing. We can help organize a focused search, arrange showings or discuss preparing a property for sale.
Local resource: Sonoma County community directory. Check official information for the address you are considering; area descriptions do not establish a property’s permitted uses.
