Boulder County, CO Fence Regulations: Height Limits (2026)

Beyond height, Boulder County's P/28 sets several construction requirements for unincorporated-area fences: fences of any height cannot interfere with the sight triangle at intersections (which varies with posted road speed, coordinated through the Transportation Department); fences must not sit in the road right-of-way; and any fence in or adjacent to a drainage easement or swale must not impede stormwater. In a 100-year floodplain, fences require a Floodplain Development Permit and must follow open-fence design standards, for example open barbed or barbless wire fencing may have no more than one horizontal strand per foot of height. If a parcel went through a Land Use review (Site Plan Review), wildlife-safe fencing may be a condition of approval.