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Buyer's Property Brief · Off-Market Diligence

Bloomfield Farms

4707 Bloomfield Rd, Petaluma (Bloomfield), CA 94952 · APN 027-050-022 · 113 acres · compiled 2026-06-13

A prospective buyer's working summary of Bloomfield Farms — a 113-acre agriculturally-zoned working ranch in the Petaluma West dairy belt, off-market since December 2025. The property runs three overlapping operations: an organic farm with a wedding/event venue, an equestrian boarding facility, and a newly-approved 2.5-acre cannabis cultivation site. This brief consolidates the seller's disclosure packet, the county record (Permit Sonoma, Assessor & GIS, CEQAnet), and the title prelim into the facts that drive a purchase decision — with particular attention to the three things that shape value here: the absence of a residence, the cannabis entitlement and its title-insurance friction, and the post-close tax-structuring opportunity.

113 acres LEA B6 160 Cannabis UPC19-0012 approved No residence on parcel No Williamson Act Petaluma West / Burnside corridor

What it is: a 113-acre working ranch owned since 2001 by Robert L. Hanson (CEO of The Duckhorn Portfolio) and Michael Agins, vested in Bloomfield Farms, LLC. The asset stack is unusually deep — an 8-stall equestrian facility, a restored 120-year-old barn, a seasonal tent-cabin campground, three wells, 2.5 miles of no-climb fencing, a heritage orchard — and it now carries a fully-approved 5-year cannabis cultivation permit. But there is no principal residence: the original was demolished in 2001 and never rebuilt.

The three things a buyer must underwrite: (1) the residence gap — a buyer underwrites a 2–3 year, $4.5–7M custom build on top of the purchase; (2) cannabis — Fidelity won't insure a cannabis-associated transaction, so the entitlement is as much a structuring liability as an asset; and (3) taxes — a purchase resets the assessed value under Prop 13, but a layered Williamson Act + conservation-easement play can claw much of that back. All three are covered below.

At a glance

Address
4707 Bloomfield Rd, Petaluma (Bloomfield village), CA 94952
APN
027-050-022 · Tax Code Area 057-002
Owner of record
Bloomfield Farms, LLC — Robert L. Hanson + Michael Agins (live in SF; parcel run as a working ranch)
Acreage
113 acres (~4.92M sq ft; GIS outline 106.7 ac)
Zoning
LEA B6 160 (Land Extensive Agriculture, 160-ac min density) · RC50/50
Williamson Act
No contract — unusual for 113 LEA acres; a post-close opportunity, not an inherited shield
Acquired
2001-02-15 for $950,000 (prior sale 1990 at $475,000)
2025-26 assessed value
$1,671,426 (Land $1,337,688 + Improvements $333,738) — well below market
2025-26 property tax
$18,258/yr — resets at sale under Prop 13
Cannabis permit
UPC19-0012 — approved 2026-04-28, NOD filed 2026-04-30; 5-yr limited term, 15,000 sf cultivation + processing
Active debt
$1,740,000 credit-line deed of trust (JPMorgan Chase, assigned from First Republic 2023)
Title & escrow
Fidelity National Title (FSNX-6062500719CAI) — will not insure cannabis-associated transactions
Schools / fire
Shoreline Joint Unified · Bloomfield VFC (volunteer), Cal Fire SRA, Moderate FHSZ
Coordinates
38.333756, −122.842983

The land & what you can do with it

The parcel is zoned LEA B6 160 — Land Extensive Agriculture at a 160-acre minimum density. At 113 acres it is under that minimum, so residential and subdivision potential is capped: this is a single working-ranch parcel, not a development play. The dominant land uses are grazing/pasture (most of the 113 acres), the building cluster (equestrian + restored barn + campground), and the ~2.5-acre cannabis pad built on engineered fill over a former quarry floor on the west side.

Hazards are modest but real. The parcel-report flags "few landslides / mostly landslide / surficial deposits," and the seller discloses a recurring soil slump on the west side below the four water tanks during heavy-rain events (remediated by tractor "a few times in 24 years"). A year-round creek crosses the property. Any residence pad or new cannabis building on the west side warrants an independent geotechnical review.

Price & comparables

The seller has not stated an asking price — the packet is intentionally price-less, with offers solicited off-market. The independent buyer-side model, corroborated by a 14-property closed-sale comp set inflation-adjusted to May 2026, puts the most-probable market-clearing close at $6–8M (median pull ~$6M), with a recommended opening offer of $4.8–5.8M. Three converging large-acreage anchors in the last 21 months frame the land value:

ScenarioRangeBuyer profile
Passive lifestyle$4.5–6MCarries the property without optimizing operations
Most-probable close$6–8MLifestyle buyer who builds the residence + runs modest equestrian
Operator-optimized$8–10MCannabis + equestrian + ag at full operation
Ceiling$10–12MOutlier; above this, finished Sonoma estates compete
Anchor comp (last 21 mo)Adj. priceAcres$/acNote
4300 Browns Lane$2.59M100$25,900<1 mi from subject; small old home
5000 Carroll Rd$5.78M234$24,6651900 farmhouse on 234 ac
5335 Burnside Rd$7.41M211$35,100The Burnside-corridor anchor
105 Purvine Rd$10.29M71$144,900Ceiling anchor — finished estate

Three drivers compress the price below the seller's likely $12–17M+ ask: no principal residence (buyer underwrites a $4.5–7M build over 2–3 years — not the seller's inflated $8.3–11.2M bid range), carrying costs of $200–250K/yr (NPV ~$2.5M over a 20-year hold), and the reality that the cannabis entitlement is more often a negotiation liability than a premium for lifestyle buyers. This is an analytical estimate, not an appraisal.

Taxes & the Williamson Act — the structuring opportunity

The property carries no ag-tax instrument on title — no Williamson Act contract, no conservation easement, no open-space contract. The sellers declined to encumber the land. That means the single biggest tax event at close is the Prop 13 reassessment from the current $1.67M assessed value up to the purchase price. At a representative ~$4.3M close, expect ~$47K/yr in property tax (≈1.1% effective), versus the current $18,258 — and a future house adds its own ~$50–77K/yr.

Every tax-saving structure is therefore a post-close opportunity the buyer executes, not an inherited shield. The recommended play is layered:

Williamson Act enrollment~½ the bill
Re-assesses the grazing acreage at agricultural-use value: cuts the ~$47K bill to roughly $20–27K/yr. The catch is a real commercial-ag requirement (a grazing lease clears the ≥$2,000/yr non-horse-ag bar — horses don't count), a 10-year rolling lock that runs with the land, and a 5-acre cap on all non-ag uses combined (house compound + cannabis pad + arenas + any classroom). Commercial camping is prohibited outright and the wedding business doesn't fit — both must end to qualify. Exit: 9-year wind-down, or ~$540K to cancel early.
Conservation easementCash + deduction
Sell or bargain-sell development rights to Sonoma Ag + Open Space (PACE), MALT, or Sonoma Land Trust. Yields cash at close, a federal §170(h) charitable deduction, and a permanent assessed-value reduction — no fixed term, no exit fee, but irreversible. Stacks with Williamson. Carve the cannabis envelope out (cannabis is prohibited on Ag + Open Space easement land). First live call was with Mel Lozano at Sonoma Land Trust.
Lessor's exemption (charter school)Sleeper
If the planned ag-education / homeschool program affiliates with an existing independent-study charter (a "public school" for tax purposes) and the barn-classroom is leased to it, the program footprint comes off the tax roll entirely — no 501(c)(3) needed, just a BOE-263 filing. The only tool in the stack that shelters improvements; tax savings must pass through as reduced rent to the school.

Net: a buyer who executes Williamson + easement + ag-building exemptions can cut the post-reassessment carry 40–60%. Engage a Sonoma land-use attorney + a §170(h)-experienced tax advisor before close. Cannabis is a "compatible," not a "qualifying," use under Sonoma's Uniform Rules — confirm county treatment before relying on it.

Cannabis entitlement (UPC19-0012)

The cannabis permit is fully approved — Final Conditions of Approval issued 2026-04-28, Notice of Determination filed 2026-04-30. It is a 5-year limited-term permit covering 15,000 sq ft of cultivation plus processing and propagation on the 2.5-acre pad, and it is grandfathered under the pre-2026-07-01 ordinance, so the new 1,000-ft residential setbacks don't apply (a fresh application here likely couldn't be permitted). That grandfathering is the real, if modest, value driver.

It comes loaded with conditions a buyer inherits if they keep it: a 1.0 acre-foot/yr water cap and a 250,000-gallon rainwater catchment required before operation; mandatory primary ag use including sheep grazing (Condition 29 — which conveniently doubles as the Williamson qualifying use); a Sept 1–Oct 31 ground-disturbance window; a 30-ft right-of-way dedication along Bloomfield Rd; and a workforce-housing in-lieu fee on new construction. And critically, vesting is gated on abating the unpermitted lower-barn kitchen (Condition 34) before the operating certificate issues.

Improvements & infrastructure

Seller-claimed capital improvements since 2001 exceed $8.8M (directional, unaudited). The major assets:

The pattern worth noting: 6 recorded Notices of Agricultural Exemption (2002–2018) explain why assessed improvements are only $334K — many structures were built ag-exempt without standard permit review. Combined with the 2014 + 2018 wedding-permit violations, a buyer should price a $50–100K contingency for unpermitted-work surprises and walk the site before relying on any structure's status.

Grazing & fencing plan

A cattle/sheep grazing lease is the operational linchpin: it clears the Williamson ag-income bar, satisfies cannabis Condition 29's sheep-grazing mandate, and turns otherwise-idle pasture into a qualifying ag use. The working plan assumes the 2.5-mi perimeter is already fenced and adds interior cross-fencing for rotational paddocks, a fenced house yard, and an exclusion around the barn / glamping / event cluster.

Interactive · accessory map
Fence-planning map →
Satellite parcel map with a 200-ft grid, a draw-to-measure tool (read fence length in feet), and our draft 4-paddock layout: ≈8,600 ft of new interior fence, ~7 gates, four ≈25-acre paddocks, a 1.8-ac house yard, and a 6.7-ac barn/event exclusion. Printable for hand mark-up.
Open the fence map →

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