Best Realtors in San Geronimo, CA (2026 Guide)
By Matthew Martinez
San Geronimo is a small unincorporated village of about 580 people in the middle of the San Geronimo Valley in central Marin, between Woodacre and Forest Knolls along Sir Francis Drake Boulevard. Homes sit on the valley floor near San Geronimo Creek and on the wooded and grassy slopes above it, with open space all around, so septic, creek setbacks and fire exposure shape most purchases.
This guide is published by Diamond Real Estate Group, one of the brokerages listed. Our broker is listed first; other agents are in alphabetical order. The order is not a ranking, and inclusion is not an endorsement.
How we chose the agents in this guide
Each agent below met three checks in October 2026:
- A current California license. We opened each agent’s record on the California Department of Real Estate (DRE) public lookup and confirmed the name, license type (salesperson or broker) and a "Licensed" status. We left out anyone whose record showed a suspension, an expired license or a responsible broker that did not match the brokerage on their profile.
- A named brokerage. Each agent’s DRE record shows the brokerage they work under, and it matches their profile.
- A public profile that names San Geronimo or its valley. We opened each agent’s profile. Three name San Geronimo or the San Geronimo Valley. Because few profiles name the village, three others name the neighboring valley villages of Woodacre or Forest Knolls instead, and the table says so plainly.
We did not rank agents, and we did not consider sales volume, reviews or awards. Licenses and affiliations change, so check the license yourself before you sign anything, and interview more than one agent.
San Geronimo housing in numbers
| Census measure (ACS 2024 5-year) | San Geronimo CDP |
|---|---|
| Population | 583 |
| Housing units | 207 (±99) |
| Median value of owner-occupied homes | $1,175,500 (±$414,303) |
| Median household income | $171,932 (±$106,258) |
| Persons per household | 2.8 |
| Median age | 46.5 |
Source: U.S. Census Bureau American Community Survey 2024 5-year estimates, as presented by Census Reporter. The margins of error are very wide for a place this small; treat these as rough guides, not current sale prices.
With about 200 homes, San Geronimo has only a few sales in a typical year. Lot size, creek frontage, septic condition and sun exposure all move value, so ask an agent for recent valley sales of similar homes rather than relying on the median.
The valley floor, San Geronimo Creek and the community plan
San Geronimo has no city government; Marin County handles zoning and permits under its inland Title 22 code, and the village is outside the Coastal Zone. The San Geronimo Valley Community Plan, adopted on December 2, 1997, treats San Geronimo as one of four valley villages with Woodacre, Forest Knolls and Lagunitas. It notes the valley floor’s high winter water table, says a leach field generally needs about an acre, and describes the valley floor as one of the most important coho salmon and steelhead spawning and nursery areas in the Lagunitas Creek watershed. For more, see our San Geronimo real estate guide and nearby Woodacre.
Costs and rules specific to a San Geronimo purchase
- Transfer tax. The Marin County Recorder’s transfer tax sheet lists the county documentary transfer tax at $0.55 per $500 of value ($1.10 per $1,000). San Geronimo is unincorporated, so no city tax applies: about $1,293 on a $1,175,500 sale. Who pays is negotiable; confirm it on your escrow estimate.
- Septic. The County’s San Geronimo and Woodacre wastewater Q&A reports failing systems in the valley caused by poor soils, high groundwater, small parcels and age, and the County’s community wastewater work centers on Woodacre and San Geronimo Flats. Pull the Environmental Health file and order a septic inspection before you remove contingencies.
- Creek and coho habitat. Work near San Geronimo Creek can face county streamside review; check the FEMA Flood Map Service Center for creekside homes and ask about any setbacks before planning an addition.
- Short-term rentals. Stays under 30 days need a county license under Chapter 5.41, with licenses capped and issued from a waitlist through the county STR program.
- Fire hazard and AB 38. Check the address on the State Fire Marshal’s Fire Hazard Severity Zone maps. In High and Very High zones, sellers may need to provide AB 38 defensible space documentation.
San Geronimo agents with verified licenses
Matthew Martinez, Diamond Real Estate Group (publisher of this guide)
Matthew Martinez is the Founder, CEO and Managing Broker of Diamond Real Estate Group. He is based in Sonoma County; contact him to discuss a purchase or sale in San Geronimo. Contact Matthew · Broker #01869679 · Diamond Group Estates Inc DBA Diamond Real Estate Group, DRE #02163490
| Agent | Brokerage | License | Areas named on profile |
|---|---|---|---|
| William Barrett | Compass | Salesperson #01917077 | San Geronimo, Woodacre, Forest Knolls, Lagunitas, Nicasio; West Marin |
| B.G. Bates (licensed as Beverly Gay Buttemiller Bates) | Golden Gate Sotheby’s International Realty, San Rafael | Salesperson #00968254 | San Geronimo Valley, Nicasio, Point Reyes Station; West Marin |
| Charlynn Baumsteiger | Coldwell Banker Realty, Greenbrae office | Salesperson #01945066 | Woodacre (neighboring village, not San Geronimo), Fairfax, Nicasio; West Marin |
| Kris Klein | Coldwell Banker Realty, Greenbrae office | Salesperson #01934328 | Woodacre (neighboring village, not San Geronimo), Ross, Greenbrae |
| Michela Rizzo McCurdy | Compass | Salesperson #01974228 | San Geronimo Valley, Woodacre, Forest Knolls, Nicasio; West Marin |
| Rick Trono | Compass | Broker #01045523 | Forest Knolls (neighboring village, not San Geronimo), Nicasio; West Marin |
Compass agents are licensed under Compass California II, Inc. (DRE #01527235); Rick Trono is a broker associate there. Charlynn Baumsteiger and Kris Klein are licensed under NRT West, Inc. (DRE #01908304), the broker for Coldwell Banker Realty. B.G. Bates is licensed under Decker Bullock Dreyfus Inc. (DRE #02027353), whose DRE record lists Golden Gate Sotheby’s International Realty as a business name; her profile is on homes.com, a listing site.
How to vet a San Geronimo agent
- Ask about valley sales. Ask how many San Geronimo Valley sales the agent has handled and which comparable sales they would use.
- Start with septic. Ask how they handle septic inspections and County Environmental Health records, and whether the home is in a wastewater project area.
- Check the creek. For homes near San Geronimo Creek, ask about flood history, setbacks and any past restoration work on the parcel.
- Plan for fire-zone rules. Ask about the fire hazard zone, defensible space and AB 38 documentation.
- Compare permits with what was built. Ask for the County permit history for decks, studios and second units.
- Check the license yourself. Confirm a "Licensed" status with a current broker on the DRE lookup.
San Geronimo questions we hear
Is there a city transfer tax in San Geronimo?
No. San Geronimo is unincorporated, so only the county tax of $0.55 per $500 applies, per the Marin County Recorder.
Who handles permits in San Geronimo?
Marin County, under its Title 22 development code and the 1997 San Geronimo Valley Community Plan.
Is San Geronimo on sewer?
Generally no; homes in the valley use septic systems. Ask County Environmental Health about the specific parcel.
Why do some agents name Woodacre or Forest Knolls instead?
Few profiles name San Geronimo itself. We included agents whose profiles name the neighboring valley villages and labeled each one in the table.
Sources & notes
- California DRE public license lookup (individual records linked in the table)
- Census Reporter, San Geronimo CDP (ACS 2024 5-year)
- Marin County Recorder, documentary transfer tax
- San Geronimo Valley Community Plan (1997)
- Marin County, San Geronimo and Woodacre wastewater Q&A
- Marin County Code Chapter 5.41, Short-Term Rentals (GoCodebook); Marin County STR program
- FEMA Flood Map Service Center; CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones
- Agent profiles on compass.com, coldwellbankerhomes.com and homes.com, linked in the table
- License records checked October 2026 on the California DRE public lookup. Last reviewed October 2026 by Matthew Martinez.
Nearby agent guides: Woodacre · Nicasio
Related: San Geronimo real estate guide · San Geronimo home valuation · Marin County agents guide · 20 tips for choosing a real estate agent
License-status update: the linked California DRE public records were checked November 2, 2026 and showed "Licensed." Public profile research retains the dates stated above. Names on DRE records may differ from public profile names; verify status and brokerage before selecting an agent.
