La Plata County, CO Landscaping Rules: Tree Removal & Heritage Trees (2026)

Section 70-8, Avoidance of Natural Hazards and Protection of Sensitive Lands, contains the county's tree removal restriction in subsection X. It lists tree removal first among the activities prohibited on steep slope areas of thirty (30) percent or greater, next to clearing, excavation, grading, construction and reconstruction. The section sets no tree-by-tree permit. The trigger is slope and location, not the size or species of the tree.

The standards apply to new development and land disturbance on land that contains the natural resources, steep slope areas, habitat or hazard areas the section addresses. Three exemptions apply: agricultural operations and structures; minor land disturbing activities that disturb less than 5,000 square feet in area and less than 18 inches in depth and need no building permit; and oil and gas drilling, which chapter 90 covers.

Steep slope areas are delineated on USGS quadrangle maps, or by a field-prepared or aerial topographic survey with a two foot or smaller contour interval at a scale of not less than one inch equals one hundred feet, certified by a licensed surveyor or professional engineer. Slope is computed on the existing land before any grading.

Five exceptions lift the prohibition: passive recreation including unpaved public trails for non-motorized use, open space and conservation uses, utilities, roads and driveways meeting subsection XI, silvicultural operations as required for wildfire mitigation or forest health, and single family homes meeting subsection XII. Under XI, utilities, driveways and roads cannot cross slopes greater than fifty (50) percent, and roads and driveways cross slopes of thirty percent or greater only if no other alternative exists and the cumulative steep slope segments do not exceed twenty (20) percent of the total length. Under XII, new single-family subdivisions cannot establish new building envelopes on steep slopes, and a home on an existing legal lot needs a geologist or professional engineer to certify the site geology plus a geotechnical evaluation.

Elsewhere in the section, clear cutting or other large-scale removal of vegetation is prohibited in avalanche path starting zones, and vegetation cannot be removed from unstable slopes unless slope integrity can be maintained. Section 70-17 separately bars planting ash, cottonwood (with one exception), tamarisk, Siberian elm and Russian olive.