Mosiman acquisition (prior owner per city-data header “Tom Birse et al” — Birse remains owner of adjacent 3858 Bloomfield = APN 025-100-024)
2009-06-15
2009R057779
(non-sale)
Trust transfer
Transfer into the Mosiman Family Trust — explains “Mosiman Steven T TR & Mosiman Helen C TR” title style
No subsequent transfer on record. Holding period = ~17.6 years as of May 2026.
Note: Sonoma County does not post recorded document images online (CA Govt Code §27200 et seq). To pull the 2008R096841 deed image, request via https://crarecords.sonomacounty.ca.gov/Web/ (accept disclaimer, search by document #) or in person at 585 Fiscal Drive, Santa Rosa.
Owner of record
Field
Value
Title style
MOSIMAN STEVEN T TR & MOSIMAN HELEN C TR
Steven T. Mosiman
Age 68 (May 2026)
Title held since
2009-06-15 (trust transfer); originally acquired 2008-10-24 as individuals
Title prior
Tom Birse / “Tom Birse et al” (consistent with adjacent 3858 Bloomfield ownership pattern; deed-image confirmation required)
Likely the secondary structure (1971 vintage — barn / equipment shed / second outbuilding). Worth a site walk to identify.
Total building footprint
2,352 sf
mixed
Three improvements on the assessor roll
Use code: 0541 — Pasture With Residence (Agricultural category).
Land
Field
Value
Acres
51.15 (LandSizeAcres); Shape__Area = 2,158,166 sf state-plane ≈ 49.5 ac geometric
Parcel shape
Elongated, ~7,207 ft perimeter, extending east from Bloomfield Rd to ridge
Centroid
38.33649, -122.82852
Two soil bands
SnD2 (Steinbeck loam, flatter, west near Bloomfield Rd) + LsE (Los Osos clay loam, steeper, east)
House location
Inferred to be in the flatter SnD2 zone
Zoning (authoritative GIS)
Field
Value
BASEZONING
LEA B6 160
DISTRICT
LEA (Land Extensive Agriculture)
DENSITY
B6 160 (1 dwelling unit per 160 ac maximum)
General Plan Land Use
Land Extensive Agriculture (LEA)
Note: The Permit Sonoma JSON parcel-report also returned “OAK SR” overlays. The Sonoma_Zoning FeatureServer’s main layer schema returns only BASEZONING/DISTRICT/DENSITY — combining overlays (OAK, SR, RC, P, TS, Z) are in separate map services. The Permit Sonoma report is authoritative for combining-district determinations.
Williamson Act
Field
Value
Contract #
null
Effective
null
Expiration
null
IsRestricted
0
NonRenewal
0
Not under Williamson Act. For contrast, immediately-north neighbor LaForge (APN 025-100-043, 3225 Bloomfield, 493.73 ac irrigated vineyard) holds Williamson contract 02-375 effective 1972.
Hazards
Hazard
Value
Source
Fire Hazard Severity Zone
Moderate in State Responsibility Area (SRA)
CALFIRE FHSZ FeatureServer
Fire District
Gold Ridge Fire Protection District (HQ 4500 Hessel Rd Sebastopol; Wilmar station 3825 Bodega Ave)
goldridgefire.org
FEMA Flood Zone
Zone X — minimal flood hazard (outside SFHA)
FEMA NFHL
Major fire perimeter overlap (2017 Complex / 2019 Kincade / 2020 LNU / 2020 Glass)
None
Permit Sonoma RESA fire layers
USGS Landslide trigger points (1997)
None within parcel bounding box
USGS layer
California Tiger Salamander
Within potential range; likely outside designated critical habitat (USFWS excluded most Sonoma parcels in 2005 final rule)
USFWS ECOS, 70 FR 44301 (2005-08-02)
Water & soils
Field
Value
Groundwater Subbasin (DWR Bulletin 118)
1-059 Wilson Grove Formation Highlands
SGMA priority
Recently elevated to Medium — managed jointly by Marin Co., Sonoma Co., City of Petaluma, City of Sebastopol. No GSP currently published.
Sonoma county-specific groundwater class
Likely Class 3 (Marginal) — verify with parcel report
SnD2 soil (Steinbeck loam, 9–15%)
Storie Index 52, Hydrologic Group C, moderately well-drained, Farmland of Statewide Importance, Ultic Haplustalfs
LsE soil (Los Osos clay loam, 15–30%)
Storie Index 15, Hydrologic Group D, well-drained, not prime farmland, Typic Argixerolls
Schools
Level
School
District
Elementary
Apple Blossom Elementary (K-3) and Orchard View (TK-8 alternative)
Twin Hills Union Elementary School District (700 Watertrough Rd, Sebastopol)
Middle
Twin Hills Charter Middle (4-8)
Twin Hills Union ESD
High
Analy High School
West Sonoma County Union HSD (462 Johnson St, Sebastopol)
Caveat: county schools layer is points (not polygon district boundaries); elementary assignment is regionally inferred and worth verifying via the WSCUHSD School Locator.