Frostline.info

Frost line depth in Gunnison County, Colorado

Frost reaches about 53 inches in typical soil across Gunnison County, from 38″ in the mildest ZIP code to 58″ in the coldest. Codes in this climate commonly set footing depth at 42 to 66 inches.

Severe frost
Estimated frost depth
53″
typical silt/loam soil
Typical code footing depth
42–66″
rule of thumb for this climate
Design freezing index
2,914
°F-days, 100-year winter
ZIP codes covered
8
#2 of 64 counties in CO (1 = deepest)
53″ 0″12″24″36″48″60″72″84″ ground frozen
Est. frost (typical soil) Typical code footing depth Clay–sand range

Frost depth by soil type

Soil typeEst. frost depth
Sand / gravel (drains well)67″
Silt / loam (typical yard soil)53″
Clay (holds water)46″

County average. Methodology.

Verify before you dig. These are climate-based estimates. The legally required frost depth is the figure your building department publishes in its IRC Table R301.2 (climatic and geographic design criteria). Call the Gunnison County building or permitting office in Colorado and call 811 before digging.

Frost depth by ZIP code in Gunnison County

ZIPCityEst. frostCode range
81210Almont58″48–72″
81220Cimarron38″30–48″
81224Crested Butte55″48–66″
81230Gunnison58″48–72″
81237Ohio City57″48–72″
81239Parlin57″48–72″
81243Powderhorn54″42–66″
81434Somerset46″36–60″

What this means for your project in Gunnison County

Deck footings & piers

Footings must bear below the frost line and at least 12″ below undisturbed ground. For planning in this area, budget for holes around 66″ deep until your permit office confirms the exact figure.

Fence posts

Set posts at least one-third of their above-ground height. Where frost heave is a problem, carry concrete footings below the frost line (about 53″ here in typical soil) and bell or taper the bottom.

Water & irrigation lines

Bury supply lines below the frost depth. Your water utility or plumbing code sets the minimum cover; in a climate this cold, 4 feet or more is common for service lines.

Slabs & frost-protected foundations

Frost-protected shallow foundations (IRC R403.3) use the 100-year air freezing index — 2,914 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather stations used

NOAA weather stationDistance100-yr AFI
Gunnison, CO6 mi3,447
Cochetopa Creek, CO17 mi3,232
Crested Butte, CO17 mi3,085
Taylor Park, CO24 mi3,429

Nearby counties

Common questions

What is the frost line depth in Gunnison County?

About 53 inches in typical soil, based on NOAA's 100-year air freezing index. Across the county's ZIP codes the estimate runs from 38 to 58 inches.

How deep should footings be in Gunnison County, Colorado?

Codes in climates like this commonly require 42 to 66 inches. The Gunnison County building department publishes the required frost depth in its adopted code (IRC Table R301.2).

Does frost depth vary within Gunnison County?

Yes. Estimates differ by 20 inches between the coldest and mildest ZIP codes, mostly from latitude and elevation. Check your own ZIP below.