Boulder County, CO Animal Ordinances: Chickens & Livestock (2026)
Key Facts
- Metric
- Animal units per acre
- Agricultural (A)
- Up to 4 units/acre
- Most rural zones
- 2 units/acre
- Residential zones
- Up to 4 weaned animals
- 1 horse
- = 1 animal unit
Summary
Boulder County limits livestock by 'animal units' per acre set in the Land Use Code zoning tables. Agricultural (A) land allows up to four animal units per acre without Special Review; most other rural zones allow two. Residential zones (RR, ER, SR) allow up to four weaned animals.
Animal units... Four animal units per acre without going through Special Review [Agricultural district]... Residents in the SR zone may keep up to 8 hens and 2 bee colonies for their own use.
Full Breakdown
The BCLUC Article 4 zoning-district tables set livestock density by animal units per acre: the Agricultural (A) district permits up to four animal units per acre without Special Review, while Forestry (F), Rural Residential (RR), Estate Residential (ER), and Suburban Residential (SR) generally allow two per acre. One horse equals one animal unit; it takes 50 chickens to equal one animal unit, so a 10-acre A parcel (40 animal units) could keep many head of livestock. In the Rural Residential, Estate Residential, Suburban Residential, and Multi-Family districts a resident may keep up to four weaned animals regardless of the unit math. Exceeding the density triggers Special Review. Right-to-farm protections under C.R.S. 35-3.5 shield established agricultural operations.
Violations & Fines
Keeping more animal units per acre than the zone allows, without Special Review approval, is a Land Use Code violation. Boulder County Community Planning & Permitting can order the herd reduced, require Special Review, or pursue zoning enforcement.
Frequently Asked Questions
How much livestock can I keep in unincorporated Boulder County?
I live on a residential lot. Any livestock at all?
Sources & Official References
Other rules in Boulder County
How Boulder County compares: Best Cities for Backyard Chickens·Compare Boulder County to another location·View the Colorado animal ordinances overview
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