Local zoning · Trinity County

Trinity County — Land Use

Land Use under the Trinity County local zoning and planning code, with the controlling citations.

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Last reviewed: July 6, 2026

Overview

In unincorporated areas of Trinity County, land use is governed by Title 17 Zoning of the County Code. Uses are controlled by the base zoning district on your parcel, then further modified by any mapped combining/overlay districts and countywide provisions. Start by confirming your base zone on the map, then read the applicable district chapter in the code and any overlays shown after the zone symbol (e.g., “SC,” “CWR”) in tandem with the base zone. See the county’s zoning & planning overview and the catalog of Trinity County Zoning districts.

In unincorporated areas, what you can do with your land is the sum of: base zoning district rules + any overlay/combining districts + general countywide standards.

Base Zoning Districts — District-by-District Land Use

Below are the districts and what they commonly allow. Each subsection interprets the ordinance; always read the cited § sections directly.

Agricultural or “A”

  • Purpose and where it applies: Working lands where agriculture is the primary land use in unincorporated areas.
  • Typical permitted uses: All agricultural uses (crop and tree farming, livestock), dairies, animal husbandry, aviaries, and a single-family dwelling are allowed by right; some intensive operations require a use permit per the next bullet (§ 17.13.010 ).
  • Uses needing a use permit: Frog or poultry farms, commercial hog and turkey raising, cattle feed yards, animal sales yards, agricultural processing plants (§ 17.13.020(A) ).
  • Key dimensional notes: Not found in retrieved materials. Verify with the jurisdiction.

Agriculture–Forest or “AF”

  • Purpose and where it applies: Resource lands supporting forestry and agriculture.
  • Typical standards: Front, side, and rear setbacks are each 20 ft, but increase to 100 ft where a yard abuts land zoned TPZ; maximum building height 40 ft; setbacks from surface water bodies are at least 200 ft or must meet California Forest Practice Act setbacks; a CalFire timberland conversion permit may be required to establish any non-forestry use (§ 17.14.070–.110 ).
  • Uses: Not found in retrieved materials. Verify with the jurisdiction.

Timberland Production Zone “TPZ”

  • Purpose and where it applies: Timber-production lands under a long-term timber use program.
  • Typical permitted/compatible uses: Growing/harvesting timber; watershed management; wildlife/fisheries habitat; timber roads and landings; portable sawmills/chippers; grazing and other agricultural uses; low-intensity recreation (hiking, hunting, etc.) (§ 17.14A.020 ).
  • Uses needing a use permit: A single-family dwelling and accessory structures; sawmill/lumber/plywood mills; trailer or public camps; public stable; short-duration labor camps; certain on-site mining for road material (§ 17.14A.030 ).
  • Parcel division standards: Not found in retrieved materials (§ 17.14A.040 referenced but details not retrieved). Verify with the jurisdiction.

Rural Residential “RR” (5‑acre minimum)

  • Purpose and where it applies: Large-lot residential and small-scale rural uses.
  • Typical permitted uses: Single-family dwelling; Christmas tree farm; forestry; orchard; row/field crops; animal keeping by ratios (e.g., 1 horse/cow per 20,000 sq ft; 3 goats/sheep per 20,000 sq ft; poultry/small livestock up to 25 per 20,000 sq ft; special ratite limits), with non-overlap of square footage counts across categories (§ 17.11.020 as reflected; ratios listed under § 17.11.020 text; ordinance confirms ratios and notes; see § 17.11.030 for permit trigger structure; and § 17.11.040–.100 for standards ).
  • Uses needing a use permit: Any use other than the listed permitted uses (§ 17.11.030 ).
  • Key dimensional standards: Minimum lot area 5 acres; minimum depth 300 ft; minimum width 100 ft; max height 40 ft; front setback 20 ft; side setback 10 ft; rear setback 20 ft; max lot coverage 25% (§ 17.11.040–.100 ).

Multiple Family “R‑3”

  • Purpose and where it applies: Multi-unit residential in areas with supporting services.
  • Typical permitted uses: Duplexes, triplexes, apartments, condominiums (§ 17.18.020 ).
  • Uses needing a use permit: Single-family dwelling; rooming/boarding; mobile home courts; churches; large day care; schools; professional offices (§ 17.18.030 ).
  • Key dimensional standards: Minimum lot area 16,000 sf; minimum width 75 ft; max height 25 ft (45 ft if within Weaverville Fire Protection District); front 20 ft; interior side 10 ft (15 ft street side); rear 15 ft; max coverage 40%; minimum 2,000 sf per dwelling unit; two parking spaces per apartment unit; drainage and encroachment approvals as specified (§ 17.18.040–.150 ).
  • Related: For site development standards, see Trinity County Development Standards and project Parking needs.

Public Facilities “PF”

  • Purpose and where it applies: Governmental, utility, educational, and other high public-importance uses.
  • Typical permitted uses: Government administrative offices, counseling, day care; library; small parks/playgrounds; post office (§ 17.29.020 ).
  • Uses needing a use permit: Airports/heliports; hospital; fire hall; sheriff’s station; fairgrounds; large parks; public parking facility; public maintenance yards; utilities; refuse disposal; caretaker units; schools; business incubators under defined criteria (§ 17.29.030 ).
  • Key dimensional standards: Max height 40 ft; exceptions-based front/side landscaping buffers where adjacent to or near residential; rear 20 ft (10 ft if alley); lot coverage unrestricted unless otherwise limited (§ 17.29.050–.090, .100 ).

Industrial (chapter 17.23)

  • Purpose and where it applies: Manufacturing, processing, and heavier commercial/industrial operations.
  • Typical heavy uses requiring a use permit include: Geothermal facilities; coal refining; nuclear power plants; lumber mill; hazardous waste treatment/hauling; septage facilities; mining/aggregate plants (batch, concrete, crushers); oil/gas drilling; explosives manufacture/storage; large-scale rendering/refining/smelting; tank farms; and other similar-intensity uses (§ 17.23.010–.030 list excerpts; CUP list includes items A–Y as shown ).
  • Accessory/signage: Accessory buildings and caretaker units allowed; on-site signage subject to county sign rules (§ 17.23.040–.050 ). See Trinity County Signage.
  • Key dimensional standards: Min parcel area 0.5 acres; min width 100 ft; max coverage 60%; max height 45 ft; minimum yards: front 25 ft, sides 10 ft, rear 10 ft; additional height possible by permit within a 5:1 floor area ratio constraint (§ 17.23.060–.130 ).
  • Parking note: Projects must meet county parking standards referenced at § 17.30.090 (cross-referenced in § 17.23.130(A) ). See Parking.

Specific Unit Development “SUD”

  • Purpose and where it applies: Master‑planned development with flexible standards where a schematic plan and guidelines control uses.
  • Land use structure: Any use(s) consistent with the approved plan/guidelines may be permitted upon obtaining a planning commission use permit (§ 17.24.030 ).
  • Minimum area: 20 acres minimum to qualify; subsequent parcel sizes vary per the approved plan/guidelines (§ 17.24.040 ).

Open Space “OS”

  • Purpose and where it applies: Areas with significant wildlife habitat or lands unsuitable for development due to public health and safety.
  • Typical permitted uses (no use permit): Forestry/tree farming; habitat enhancement approved by state/federal wildlife agencies; pasture/grazing; other similar uses as determined by the planning commission (§ 17.25A.020 ).
  • Uses needing a use permit: Low‑intensity recreation with minor improvements; mining; public/private road development (§ 17.25A.030 ).

Recreation Development “RD‑1”

  • Purpose and where it applies: Trinity Unit of the Whiskeytown–Shasta–Trinity National Recreation Area, balancing recreation, conservation, and resource protection (§ 17.26.008 ).
  • Uses and standards: Allowed uses are limited to those listed in chapter 17.26 and similar uses per § 17.30.010; details beyond the stated purpose were not fully retrieved (§ 17.26.005–.010 ). Verify with the jurisdiction.

Overlay and Combining Districts That Modify Land Use

  • Scenic Conservation “SC” overlay. Applies where “SC” follows the zone symbol. All underlying permitted uses remain allowed, but a planning director use permit is required for placement of buildings, development of public/private roads or driveways, decks/boat landings/wells, and for certain vegetation removal (mechanized removal of trees/bushes ≥20 ft tall); exceptions apply if reviewed in a Timber Harvest Plan or other environmental document (§ 17.25.010–.050 ). See Overlay Districts and Design Review.
  • Critical Water Resource “CWR” overlay. Applies where “CWR” follows the zone symbol. Prior to any parcel division, you must prove water quantity/quality using specified methods (e.g., on-site well producing ≥1.5 gpm, springs, or a public water system; lab analyses may be required). Certain divisions with no water demand may be marked “CWRN” and then are ineligible for building/septic permits (§ 17.29A.010–.040 ).
  • Flood Hazard “FH” overlay. Establishes the county’s framework for flood hazard regulation and findings of fact; detailed siting/standard provisions were not fully retrieved (§ 17.29B.010–.020 ). Verify with the jurisdiction.
  • Special Building Site Area “B‑1/B‑2/B‑3” combining districts. Override standard parcel area/width where combined with a base zone: B‑1 = 10,000 sf and 100 ft width; B‑2 = 15,000 sf and 100 ft width; B‑3 per zoning map (§ 17.28.010(A)–(C) ).

Cannabis‑Related Land Uses (where allowed by zoning)

Trinity County regulates commercial cannabis uses by activity and zoning district, with buffers and opt‑out areas. The table below summarizes where uses may occur in unincorporated areas, in addition to any site‑specific permitting.

Activity Allowed zoning districts (permit type) Key exclusions/buffers Code Reference
Nurseries (Type 4) A; C‑3; M‑1/M‑2; I; SUD (industrial‑identified parcels); AP Not allowed in RD‑1 nor Ruth Lake SUD; ≥1,000 ft from youth facility/school/church/residential treatment; ≥500 ft from authorized school bus stop unless variance (§ 17.43A.020–.030) § 17.43A.020–.030
Distribution (Type 11) C‑2; C‑3; I; A; SUD (industrial‑identified); AF (all as CUP) ≥1,000 ft from youth facility/school/church/residential treatment; ≥500 ft from school bus stop unless variance (§ 17.43B.020–.030) § 17.43B.020–.030
Manufacturing (Types 6/N/P) C‑2; C‑3; I; A; SUD (industrial‑identified); AP; AF; microbusiness with low‑impact extraction may be in RR or U (all with appropriate permits) Prohibited in NPS/USFS recreation areas, Ruth Lake CSD lease lots, and listed community “opt‑out” areas; 1,000‑ft/500‑ft buffers apply (§ 17.43F.020, .040) § 17.43F.020, .040
Processing (Processor license) CUP in C‑2 and C‑3; Director’s Use Permit in I, A, SUD (industrial‑identified), AP, AF Prohibited in Whiskeytown‑Shasta‑Trinity NRA, Ruth Lake CSD lease lots, and listed “opt‑out” areas; self‑processing allowed where tied to licensed cultivation, incl. certain adjoining‑county premises (§ 17.43I.020) § 17.43I.020; definitions/terms in ch. 17.43I

Selected Dimensional and Use Standards (quick reference)

District Typical permitted uses Key dimensional standards Code Reference
RR (5‑acre min) Single‑family; small‑scale ag; animal keeping per ratios Min lot 5 ac; width 100 ft; height 40 ft; front 20 ft; side 10 ft; rear 20 ft; max coverage 25% § 17.11.020–.100
R‑3 Multifamily (duplex–apartment) Min lot 16,000 sf; width 75 ft; height 25 ft (45 ft in Weaverville FPD); front 20 ft; side 10/15 ft; rear 15 ft; 2 parking spaces/unit § 17.18.020–.150
PF Public/governmental uses Height 40 ft; context‑based yards; rear 20 ft (10 ft alley); no lot coverage cap § 17.29.020–.090
Industrial (ch. 17.23) Manufacturing/processing; caretaker unit accessory Min lot 0.5 ac; width 100 ft; height 45 ft; front 25 ft; sides 10 ft; rear 10 ft; max coverage 60% § 17.23.060–.130
AF Resource lands 20‑ft setbacks (100‑ft if abutting TPZ); 200‑ft waterbody setback or per Forest Practice Act; height 40 ft § 17.14.070–.110
TPZ Timber and compatible uses; SF dwelling by CUP See allowed/conditional use lists; division standards not retrieved § 17.14A.020–.030

Countywide Provisions That Affect Land Use

  • Accessory buildings/uses: Must remain incidental to the principal use. Attached accessory structures follow primary building setbacks; detached accessory structures have countywide yard and driveway minima (e.g., 20‑ft front; 10‑ft to ROW on side/rear; 5‑ft interior sides/rear; 25‑ft max height unless increased by use permit). Early construction of certain accessory buildings has limits and may require a Director’s Use Permit (§ 17.30D.010–.040, incl. tables; zones noted include U, RR, A, AF, TPZ) (§ 17.30D.010–.040 ).
  • Temporary batch plants/portable rock units: Allowed as temporary uses with detailed fire, access, and environmental safeguards; can be permitted countywide under specified criteria (§ 17.23.020(E) with procedural detail in subitems i–vi ).
  • Signs and parking: Follow the sign ordinance and county parking rules; projects explicitly cross‑reference parking at § 17.30.090 (§ 17.23.050, § 17.23.130(A) ). See Design Review for any required aesthetic review and Parking for stall counts/layouts.
  • Combining/overlays: If your map shows SC, CWR, FH, or B‑# after your zone, those provisions add to or supersede base‑zone rules (SC and CWR explicitly state this; FH is an overlay framework) (§ 17.25.020; § 17.29A.010–.030; § 17.29B.010; § 17.28.010 ).
  • Process: Many activities change from “permitted” to “use permit required” depending on intensity, location, or overlay. For relief, see Variances and Exceptions. Nonconforming sites/uses are handled per Trinity County Nonconforming Uses.
  • Planning crosslinks: Check Trinity County Development Standards alongside your base zone. If your project involves exterior design in sensitive areas, see Trinity County Design Review.
  • Housing/ADUs: State laws may grant additional residential allowances. See California ADU law and California housing laws. Local land use still governs siting; building requirements follow the California Building Standards Code.

Checklist

  • Confirm your parcel’s base zone and any overlays on the county zoning map; then read the correct district chapter.
  • Identify whether your activity is “permitted” or requires a Director’s/Planning Commission Use Permit in your zone (e.g., A vs. intensive ag § 17.13.020; cannabis activities per ch. 17.43 series) .
  • If in SC, CWR, or FH overlays, incorporate those requirements (site placement, water proof, flood standards) (§ 17.25.030–.050; § 17.29A.020–.030; § 17.29B.010–.020) .
  • Check dimensional limits: minimum lot size/width, height, setbacks, lot coverage for your district (e.g., RR, R‑3, PF, Industrial) (§ 17.11.040–.100; § 17.18.040–.100; § 17.29.050–.090; § 17.23.060–.120) .
  • Verify accessory building limits/timing if adding garages, sheds, or ag structures (§ 17.30D.030–.040) .
  • Address parking, signage, and any needed design review early (§ 17.23.050, § 17.23.130(A)) .
  • For cannabis uses, confirm allowed zones, buffers, and opt‑out areas before site selection (§ 17.43A.020–.030; § 17.43B.020–.030; § 17.43F.020–.040; § 17.43I.020) .

Risks & Ambiguities

Issue Why it matters What to verify
Missing full text for some districts (e.g., R‑1, C‑1, C‑2) Permitted/conditional uses and standards vary significantly by district Not found in retrieved materials; confirm district chapter and § for your parcel
Industrial chapter labeling vs. zoning symbol Heavy‑use lists are in ch. 17.23; ensure it matches your mapped “I” zone Check your parcel’s mapped symbol and read ch. 17.23 standards (§ 17.23.060–.130)
RD‑1 specific use lists Recreation Area parcels have unique allowances/limits Consult ch. 17.26 and project‑area guidelines (§ 17.26.005–.010)
FH overlay development standards Floodplain rules can control elevation, siting, and use Only framework retrieved; obtain FH development provisions (§ 17.29B.010–.020)
TPZ parcel division standards Affects lot split feasibility § 17.14A.040 not retrieved; verify with the jurisdiction
Cannabis “opt‑out” maps Some communities are excluded for processing/manufacturing Confirm current opt‑out boundaries in § 17.43F and § 17.43I lists (§ 17.43F.020(E); § 17.43I.020(C))

Information Gaps

  • Detailed district chapters for Single‑Family Residential (R‑1), Two‑Family Residential (R‑2), and Commercial districts (C‑1/C‑2/C‑3) beyond cross‑references. Not found in retrieved materials.
  • Complete RD‑1 use lists and any subdistricts. Not found in retrieved materials.
  • Flood Hazard overlay technical development standards. Not found in retrieved materials.
  • TPZ parcel division criteria (§ 17.14A.040). Not found in retrieved materials.

Plain-English Summary

In unincorporated Trinity County, your base zoning district (e.g., RR, A, AF, R‑3, PF, Industrial, TPZ) sets what uses are allowed, while overlays like SC, CWR, and FH can add extra conditions. Typical rural parcels allow a home and small‑scale ag; multifamily is limited to R‑3; public facilities have their own district; industrial uses are concentrated and often need a use permit. Cannabis uses are allowed only in specific districts with buffers and opt‑out areas. Always check your map label, then read the exact § sections cited for your district.

Source References

  • Title 17 – Zoning (MuniCode export; unincorporated areas only): adoption/purpose/context (§ 17.01.010; § 17.02.010; § 17.03.010)
  • Agricultural “A” district (§ 17.13.010–.020)
  • Rural Residential “RR” district (§ 17.11.020–.110 excerpts)
  • Multiple Family “R‑3” district (§ 17.18.010–.150)
  • Agriculture–Forest “AF” standards (§ 17.14.070–.110)
  • Timberland Production “TPZ” (§ 17.14A.010–.030)
  • Public Facilities “PF” district (§ 17.29.010–.100)
  • Industrial (ch. 17.23) uses/standards (§ 17.23.010–.140)
  • Specific Unit Development “SUD” (§ 17.24.030–.040)
  • Open Space “OS” (§ 17.25A.010–.030)
  • Scenic Conservation overlay “SC” (§ 17.25.010–.050)
  • Critical Water Resource overlay “CWR” (§ 17.29A.010–.040)
  • Flood Hazard overlay “FH” framework (§ 17.29B.010–.020)
  • Special Building Site Area “B” combining districts (§ 17.28.010)
  • Accessory buildings/uses and setbacks (§ 17.30D.005–.040)
  • Cannabis nursery (§ 17.43A.020–.030) ; distribution (§ 17.43B.020–.030) ; manufacturing (§ 17.43F.020–.040) ; processing (§ 17.43I.020; definitions)

Sources

Retrieved passages

  • Trinity County Zoning Code (Chapter 17.25) High relevance
  • Trinity County Zoning Code (Section 17.25.040) High relevance
  • Trinity County Zoning Code (§ 1) High relevance
  • Trinity County Zoning Code (§ 2) High relevance
  • Trinity County Zoning Code (§ 3) High relevance
  • Trinity County Zoning Code (Section 17.30.060.) Medium relevance
  • Trinity County Zoning Code (§ 2) Medium relevance
  • Trinity County Zoning Code (Chapter 17.32) Medium relevance

Cited sections

Frequently asked questions

What can I build on a Rural Residential (RR) lot in unincorporated Trinity County?

Typically a single-family home, small-scale agriculture (orchards, row crops), and animal keeping within specified ratios are allowed. Minimum lot size is 5 acres, with 20‑ft front and rear setbacks, 10‑ft sides, and 40‑ft max height; other uses may require a use permit (§ 17.11.020–.100) .

What does the R‑3 (Multiple Family) district allow, and what are the main standards?

R‑3 allows duplexes, triplexes, apartments, and condos; single‑family and some civic/office uses need a use permit. Typical standards include 16,000‑sf minimum lot, 25‑ft max height (45 ft in Weaverville FPD), and 20/10/15‑ft setbacks; 2 parking spaces per apartment unit are required (§ 17.18.020–.150) .

Can I live on TPZ land?

A single-family dwelling and accessory structures can be allowed on TPZ with a use permit, provided they do not significantly detract from timber production. Many timber‑compatible and recreation uses are permitted/compatible outright (§ 17.14A.020–.030) .

I’m in the Scenic Conservation (SC) overlay. What triggers a permit?

In the SC overlay, the planning director must review/permit building placement, road/driveway development, certain accessory features (e.g., decks, boat landings), and mechanized removal of taller vegetation; there are exceptions if the project was already reviewed in a THP or CEQA/NEPA document (§ 17.25.030–.050) .

Do industrial uses have special yard or height rules?

Yes. Industrial standards commonly include 0.5‑acre minimum parcel, 100‑ft minimum width, 45‑ft max height, and 25/10/10‑ft yards. Some very heavy uses (e.g., energy facilities, hazardous waste, mining) require a use permit (§ 17.23.060–.130) .

Where can commercial cannabis activities operate?

It depends on the license type. Nurseries are allowed in A, C‑3, M‑1/M‑2, I, AP, and some SUD parcels; distribution in C‑2/C‑3/I/A/AF/SUD; manufacturing in various commercial/industrial/ag/resource zones; processing in C‑2/C‑3 (CUP) and I/A/AP/AF/SUD (Director’s Use Permit), all subject to buffers and opt‑out area prohibitions (§ 17.43A.020; § 17.43B.020; § 17.43F.020; § 17.43I.020) .

What happens if my parcel is in the Critical Water Resource (CWR) overlay and I want to split it?

You must prove adequate water quantity/quality before division, using methods like a qualified well or spring test, or provide public water. Some no‑water‑use splits can be marked “CWRN,” which then blocks building/septic permits (§ 17.29A.020–.040) .

Are there countywide rules for garages and sheds?

Yes. Attached accessory structures follow main‑building setbacks. Detached structures have minimum setbacks (e.g., 20‑ft front, 10‑ft from side/rear ROW, 5‑ft interior sides/rear) and a typical 25‑ft height cap unless increased by permit. Early construction of some accessory buildings requires a Director’s Use Permit (§ 17.30D.030–.040) .

I’m planning a public facility (e.g., a fire hall). Which district and what standards apply?

Public facilities belong in the PF district; many uses are permitted, while airports, hospitals, large parks, and utilities need a use permit. Height is generally capped at 40 ft, and landscaping/setback buffers apply near residential uses (§ 17.29.020–.090) .

Do I need to meet parking and sign rules in addition to land use?

Yes. Projects must comply with county parking requirements and the sign ordinance in addition to land use approvals; these are cross‑referenced in multiple district chapters (§ 17.23.050; § 17.23.130(A)) .

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