Wildfire mitigation
What goes on a wildfire mitigation checklist for a Colorado mountain home?
Wildfire mitigation on a mountain home starts at the siding and works out to 100 feet. The Colorado State Forest Service sets the numbers.
A live person answers. Not a robot, not a phone tree. Updated September 2026.
Photos: Ski lift climbing the mountain with snowy peaks, morning light, Live Kaiah (Unsplash).
The Colorado State Forest Service splits the Home Ignition Zone into three rings: 0-5 ft, 5-30 ft and 30-100 ft. Inside 5 ft, nothing burns: rock, gravel or pavers, no mulch and no firewood under the deck. From 5 to 30 ft, grass stays at 4 inches or less and tree crowns sit 10 ft apart. Firewood and propane tanks sit at least 30 ft from the home.
0 to 5 feet.
Rock, gravel or pavers. No mulch, no woody debris, no storage under the deck.
5 to 30 feet.
Grass at 4 inches or less and 10 feet between tree crowns.
30 to 100 feet.
The CSFS guide extends Zone 3 past 100 feet on steep slopes.
More than a mile.
Embers travel more than a mile and are the most common cause of home ignition, per the CSFS.
What goes in Zone 1, 0 to 5 feet from the house?
- Nonflammable ground. Rock, gravel or pavers against the foundation.
- Nothing that burns. Remove all flammable plants, mulch and woody debris.
- Clear under the deck. No firewood and no storage under decks.
- Roof and chimney. Prune branches that hang over the roof. Keep all fuels 10 feet from the chimney.
- Rake the needles. Rake pine needles within 5 feet of decks and structures.
What goes in Zone 2, 5 to 30 feet from the house?
- Mow the grass. Keep grass at 4 inches or less.
- Space the trees. 10 feet between tree crowns. Groups of 2 to 3 trees are fine with 30 feet between groups.
- Limb the trees. Prune limbs 6 to 10 feet up, or one third of the tree's height, whichever is less.
- Pull the juniper. Remove ground juniper.
- Space the shrubs. Keep shrub clumps apart by 2.5 times their mature height.
What goes in Zone 3 and along the driveway?
- Zone 3 runs 30 to 100 feet. The CSFS guide makes the zone larger on steep slopes.
- Firewood and propane at 30 feet. Set both at least 30 feet from the home and clear 10 feet around each.
- Thin the driveway. Thin trees to 10 feet of crown spacing for 30 feet on each side of the driveway.
- Forest types covered. The guide covers ponderosa pine, Douglas-fir and mixed conifer below 9,500 feet.
Check the home's wildfire risk on the Colorado Forest Atlas Wildfire Risk Viewer before you write an offer.
What home hardening belongs on the checklist?
- Class A roof. The CSFS guide calls for a Class A roof.
- Screened vents. Cover vents with 1/8-inch metal mesh.
- Siding clearance. Leave 6 inches between the ground and the siding.
- Fencing. No combustible fencing within 5 feet. Jefferson County requires noncombustible fencing within 8 feet on permitted work applied for on or after July 1, 2026.
- Jefferson County plant list. No junipers, arborvitae or Gambel oak within 30 feet on permitted work.
In the 2016 Cold Springs Fire near Nederland, 8 of 1,000 threatened homes burned. Call the Kenna Real Estate Group at 303-955-4220 to walk a home's Zone 1 before your inspection deadline.
Questions
Quick answers.
What are the three wildfire zones around a Colorado home?
Zone 1 runs 0 to 5 feet, Zone 2 runs 5 to 30 feet and Zone 3 runs 30 to 100 feet, per the Colorado State Forest Service.
How far apart should trees be for defensible space?
10 feet between tree crowns in Zone 2. Groups of 2 to 3 trees are fine with 30 feet between groups.
How far should firewood be from a mountain home?
At least 30 feet, with 10 feet cleared around the pile. Propane tanks follow the same 30-foot rule.
What causes most homes to catch fire in a wildfire?
Embers, per the CSFS. Embers travel more than a mile.
What roof does the CSFS recommend?
A Class A roof, plus 1/8-inch metal mesh on vents and 6 inches of clearance between the ground and the siding.
Sources
- CSFS Home Ignition Zone guide (2021)
- Colorado State Forest Service
- Jefferson County defensible space
- Colorado Forest Atlas Wildfire Risk Viewer
Rules, rates and dates change. The county, town or state office named above has the current version.
Go deeper
Where to go next.
The map
Where the mountain towns are.
Every pin opens that town's page. Drive times from downtown Denver, without traffic.
- Front Range foothills
- I-70 corridor
- Peak to Peak
- Summit County
- Resort
- Tap a town to open its page
Outline: U.S. Census Bureau. Roads from downtown Denver: OSRM on OpenStreetMap. Town points: OpenStreetMap and USGS. Drive times without traffic.
Private consultation
Ask us about your mountain home.
303-955-4220A live person answers. Not a robot, not a phone tree.
- Every mountain town. Evergreen and Conifer to Summit County and Steamboat.
- Wildfire, water, winter. Insurance, well, septic and access checked before you offer.
- One point of contact. From the first call to the closing table.
Colorado Mountain Home Finder is part of the Kenna Real Estate Group at Keller Williams DTC (KWDTC).