Best Realtors in Hidden Valley Lake, CA (2026 Guide)
By Matthew Martinez
Hidden Valley Lake is an unincorporated community of about 5,900 people in south Lake County, off Highway 29 between Middletown and Lower Lake. It is a planned community built around a private lake and golf course, and its homes draw retirees and commuters who drive toward Napa, Sonoma and the Bay Area.
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 with a current broker affiliation.
- A named brokerage. Each agent’s DRE record shows the brokerage they work under.
- A public profile that names Hidden Valley Lake. We opened each agent’s brokerage or listing-site profile, or the brokerage’s Hidden Valley Lake office roster, and confirmed it names Hidden Valley Lake (or "Hidden Valley").
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.
Hidden Valley Lake housing in numbers
| Census measure (ACS 2024 5-year) | Hidden Valley Lake CDP |
|---|---|
| Population | 5,872 |
| Median value of owner-occupied homes | $394,800 |
| Median household income | $84,152 |
| Persons per household | 2.6 |
| Median age | 52.6 |
| Mean travel time to work | 41.9 minutes |
| Housing units | 2,596 |
Source: U.S. Census Bureau American Community Survey 2024 5-year estimates, as presented by Census Reporter. The Census QuickFacts page did not load when we checked. Figures are estimates with margins of error.
Hidden Valley Lake’s median owner-occupied value and household income are both above the Lake County figures reported by QuickFacts ($324,300 and $60,621). Its median age of about 53 and a mean commute near 42 minutes reflect its two main groups of buyers: retirees and long-distance commuters. These are five-year survey figures, not current sale prices.
A planned community in the Middletown Area Plan
Hidden Valley Lake has no city government; Lake County sets zoning and issues permits. The County’s Middletown Area Plan, adopted August 17, 2010, covers Middletown, Hidden Valley Lake, Anderson Springs and the Langtry/Guenoc Valley, and guides land use around the community. Homes inside the planned community are subject to its association’s rules, and lots outside it may be on wells and septic.
For more on the area, see our Hidden Valley Lake real estate guide.
Costs and rules specific to a Hidden Valley Lake purchase
- Transfer tax. Hidden Valley Lake is unincorporated, and the Lake County Assessor-Recorder fee schedule lists the documentary transfer tax at $1.10 per $1,000: about $434 on a $394,800 sale. See our California transfer tax guide.
- Association documents and dues. For a home in the planned community, read the association’s governing documents, budget, dues and any architectural rules before you remove contingencies.
- Short-term rentals. The County announced in July 2026 a committee to help write short-term rental rules for the unincorporated area; association rules may add their own limits.
- Fire hazard and insurance. Look up the address on the State Fire Marshal’s Fire Hazard Severity Zone maps, read the natural hazard disclosure report and get an insurance quote early.
- Special taxes. Sellers must make a good-faith effort to disclose special tax districts under Civil Code section 1102.6b; read the tax bill for direct charges.
Hidden Valley Lake 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 Hidden Valley Lake. Contact Matthew · Broker #01869679 · Diamond Group Estates Inc DBA Diamond Real Estate Group, DRE #02163490
| Agent | Brokerage | License | Areas named on profile |
|---|---|---|---|
| Christopher Castelli | CENTURY 21 Epic, Hidden Valley Lake | Broker #01829626 | Hidden Valley Lake office |
| Rebecca Castelli | CENTURY 21 Epic, Hidden Valley Lake | Salesperson #02114588 | Hidden Valley Lake office |
| Brittney Horn | CENTURY 21 Kobetz Realty, Ukiah | Salesperson #02236306 | Hidden Valley Lake, Clearlake, Clearlake Oaks, Lucerne, Nice |
| Michelle Romero | CENTURY 21 Epic, Hidden Valley Lake and Santa Rosa | Salesperson #01296865 | Hidden Valley Lake and Santa Rosa offices |
| Jen Mullin (licensed as Jennifer Mullin) | RE/MAX Gold, Lakeport | Salesperson #01299223 | Hidden Valley, Middletown, Cobb, Clearlake, Lakeport |
| Kimberly Rupp | Navigate RE Co. | Salesperson #01480439 | Hidden Valley Lake, Middletown, Cobb, Lower Lake, Clearlake, Kelseyville, Lakeport |
| Faylen Silva | RE/MAX Gold, Lakeport | Salesperson #01772839 | Hidden Valley, Cobb, Middletown, Kelseyville, Lake County |
| Cynthia Smith (licensed as Cynthia Clemencia Smith) | RE/MAX Gold, Lakeport | Salesperson #01341797 | Hidden Valley, Middletown, Lower Lake, Cobb, Calistoga |
| Diane Sutton | Navigate RE Co. | Salesperson #01313634 | Hidden Valley Lake, Middletown, Cobb, Lower Lake, Clearlake |
| Jennifer Wall | RE/MAX Gold, Middletown | Salesperson #02037114 | Hidden Valley, Middletown, Cobb, Kelseyville, Lower Lake |
| Shannon Williams | RE/MAX Gold, Middletown | Salesperson #01705168 | Hidden Valley, Middletown, Cobb, Lower Lake, Lake County |
"Hidden Valley Lake office" means the agent appears on the roster of CENTURY 21 Epic’s office at 18983 Hartmann Road. On the DRE record, CENTURY 21 Epic agents are licensed under Century 21 Select Wine Country, Inc. (Christopher Castelli as a broker associate), CENTURY 21 Kobetz Realty agents under Kobetz Realty, Inc., RE/MAX Gold agents under Norcal Gold Inc, and Kimberly Rupp and Diane Sutton (profiles on nexthome.com) under Navigate RE Co.
How to vet a Hidden Valley Lake agent
- Ask how often they sell inside the planned community. Association rules, dues and resale paperwork are part of every sale there.
- Ask for the association documents early. Read the rules on rentals, parking, pets and exterior changes.
- Get an insurance quote first. Ask which carriers are writing policies near the address.
- Test the commute. The Census mean commute is about 42 minutes; drive your route at rush hour.
- For homes outside the community, order well and septic inspections.
- Check the license yourself. Confirm a "Licensed" status with a current broker on the DRE lookup.
Hidden Valley Lake questions we hear
Is there a city transfer tax in Hidden Valley Lake?
No city applies; the community is unincorporated, so the county rate of $1.10 per $1,000 is the transfer tax.
Who regulates building in Hidden Valley Lake?
Lake County handles zoning and permits under its zoning ordinance and the Middletown Area Plan; homes in the planned community also need any approvals its association requires.
Can I rent out a Hidden Valley Lake home short-term?
Check the association’s rules first. The County is also drafting short-term rental rules for the unincorporated area.
Do Middletown agents cover Hidden Valley Lake?
Often, yes. Most profiles in the table name both. See our Middletown agents guide and Lake County agents guide.
Sources & notes
- California DRE public license lookup (individual records linked in the table)
- Census Reporter, Hidden Valley Lake CDP profile (ACS 2024 5-year)
- U.S. Census QuickFacts, Lake County
- Lake County Assessor-Recorder, Schedule of Fees
- Middletown Area Plan (adopted Aug. 17, 2010)
- Lake County news: short-term rental ordinance committee (July 6, 2026)
- CAL FIRE Office of the State Fire Marshal, Fire Hazard Severity Zones
- CENTURY 21 Epic, Hidden Valley Lake office roster; agent profiles linked in the table
- License records checked October 2026 on the California DRE public lookup. Last reviewed October 2026 by Matthew Martinez.
Related: Hidden Valley Lake real estate guide · Hidden Valley Lake home valuation · Lake 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.
