Yellowstone County, MT Tree Protection: Parkway Planting (2026)

Section 27-1204.A requires a landscaped area at least five feet wide along any property line abutting a public or private street right-of-way, planted with street trees calculated at one tree per 50 lineal feet of frontage, rounding fractions up. Trees do not have to sit on an exact 50-foot grid: the code sets a maximum interval of 80 feet and a minimum of 25 feet, leaving exact placement within that range to the developer's landscape designer. Measurement runs from the property line inward, except along a boulevard, where it is measured from the leading edge of the sidewalk unless a drainage swale sits between road and sidewalk, in which case the property line controls again (27-1204.B).

Up to 30 percent of the required frontage landscaping may sit inside a county or private street right-of-way with permission from County Public Works or the owner's association, and the frontage strip may overlap required yards and setbacks so it does not need its own separate area. Driveways along the frontage are not subtracted from the linear footage used to calculate how many trees are required; the code instead compresses the required planting into whatever frontage remains. Species must come from the Yellowstone County Plant List, the frontage yard must be at least 75 percent organic material excluding mowed turf, and coniferous trees are barred from street frontage yards outright. Street trees specifically must be canopy-type deciduous trees with a minimum caliper of 1.5 inches at planting under the article's general plant material standards.