Yellowstone County, MT Animal Ordinances: Chickens & Livestock (2026)
Key Facts
- Unit ratio, <=2.5 acres
- 1 unit per 20,000 sq ft
- Unit ratio, 2.51-9.99 acres
- 1 per acre (fed) or 1 per 4 acres
- Hens/roosters/ducks
- 0.25 fowl unit each
- Turkeys/geese
- 0.50 fowl unit each
- Structure setback, small lots
- 50 ft from line & dwelling
- Lots exempt from unit limits
- Over 9.99 net acres
- 4-H/FFA project limit
- 6 months per 12-month period
Summary
Unincorporated Yellowstone County lets residents keep backyard chickens and other livestock under Section 27-1008, but the allowance scales with lot size: on 2.5 acres or less, the code allows one livestock or fowl unit per 20,000 square feet devoted to the animals, and hens, roosters or ducks count as 0.25 units each. Coops and barns must sit 50 feet from every property line and 50 feet from any dwelling.
A. LIVESTOCK AND FOWL
1. Where Permitted Livestock may be maintained in any zoning district as provided in Table 27-1000.3. ...
3. Use Standards
(a) Livestock and/or fowl are permitted on lots that are 2.5 net acres or less in size provided that all of the following regulations are satisfied.
(1) One livestock and/or fowl unit is allowed per 20,000 square feet of land devoted exclusively to the raising of the animal(s). Livestock or fowl that are listed in the livestock and/or fowl unit table(s) below are allowed types of animals under this subsection, with the exception of bison. ...
(4) All accessory structures used for the purpose of housing, keeping, or sheltering livestock or fowl shall be setback a distance of 50 feet from any property line and 50 feet from any dwelling.
Full Breakdown
3. 5 net acres or less, the code allows one livestock or fowl unit per 20,000 square feet devoted exclusively to raising the animals, and supplemental feeding is required. 99 net acres, the ratio loosens to one unit per acre if the animals are supplementally fed or kept on irrigated pasture, or one unit per four acres on unirrigated pasture with no supplemental feeding. 99 net acres are exempt from these unit limits entirely. 50 units each, so a 20,000-square-foot minimum lot supports up to four hens.
Bison are excluded from the standard unit calculation. 4-H and FFA project animals get a carve-out: one additional livestock or fowl unit per enrolled youth, supplementally fed, but capped at six months on the property in any 12-month period, unless the project is a breeding project, which is exempt from the time limit. 99 acres. These structures cannot occupy a required front yard in any district except the Agriculture (A) district.
Violations & Fines
Keeping more animals than the unit table allows, or housing them closer than the required setback, is a Zoning Code violation and a misdemeanor under Section 27-1704.G, punishable by a fine up to the state statutory limit, up to six months in jail, or both, with each day treated as a separate offense. The zoning coordinator in Planning & Community Services can issue a stop-use order, and 4-H/FFA project animals kept past the six-month limit lose their exemption.
Frequently Asked Questions
How many chickens can I keep on a small lot in unincorporated Yellowstone County?
How far must a chicken coop be from my neighbor's property line?
Do the livestock unit limits apply on large rural parcels?
Can my 4-H project animal stay past the fair?
Sources & Official References
Other rules in Yellowstone County
How Yellowstone County compares: Best Cities for Backyard Chickens·Compare Yellowstone County to another location·View the Montana animal ordinances overview
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