No-See-Um
No-See-Um Trail is a 10.6 miles trail in Arapaho and Roosevelt National Forests, Colorado. The Forest Service rates it trail class 2 to 3, moderately developed to developed. It is open to hiking, horse and pack stock, mountain biking, motorcycle, atv, e-bikes, snowmobile, snowshoeing and cross-country skiing.
Trail conditions, closures and hazards are not tracked here. The Arapaho and Roosevelt National Forests official page carries current alerts and closure orders.
Map
One end Other endLine simplified to about 100 metres. Basemap from the USGS National Map.
| One end | 39.8937, -106.0895 · Directions ↗ |
| Other end | 39.8937, -106.0895 · Directions ↗ |
The ends are the two ends of the longest connected chain of segments. The record does not say which is the usual start. The trail is recorded as 4 segments.
The trail
| Length | 10.6 miles |
| Trail class | 2, moderately developed; 3, developed |
| Type | snow trail, land trail |
| Surface | native material, snow |
| Typical grade | 12-20 percent, 5-8 percent |
| Typical tread width | 18-24 inches, 48-60 inches |
| Motor vehicles | Open to at least one motorized use |
| Accessibility | Not evaluated |
| Trail numbers | 146, SNO-146 |
| Forest | Arapaho and Roosevelt National Forests (unit 0210) |
| States | Colorado |
| Detail published | management level, with uses |
Values are the set across all segments. Class 1 is minimally developed and class 5 is fully developed. Grade and width are the forest's typical values, not measured extremes.
Allowed uses
| Hiking | Allowed 06/15 to 11/15 (month/day) |
| Horse and pack stock | Allowed 06/15 to 11/15 (month/day) |
| Mountain biking | Allowed 06/15 to 11/15 (month/day) |
| Motorcycle | Allowed 06/15 to 11/15 (month/day) |
| ATV | Allowed 06/15 to 11/15 (month/day) |
| E-bikes | Allowed 06/15 to 11/15 (month/day) |
| Snowmobile | Allowed 11/16 to 05/31 (month/day) |
| Snowshoeing | Allowed 11/16 to 05/31 (month/day) |
| Cross-country skiing | Allowed 11/16 to 05/31 (month/day) |
A use is listed when the Forest Service records it as managed, accepted or discouraged on any segment. Discouraged still means legal. Uses marked restricted are left out. Where the forest publishes a Motor Vehicle Use Map, that map governs motorized use.
Trailheads
The Forest Service recreation layer records no trailhead within a third of a mile of this trail's line. Many trails start from a road pullout or another trail with no trailhead record. The forest's recreation pages list the trailheads it does publish.
Distance is from the point to the nearest part of the trail line. Season text is what the forest wrote and is often a season name rather than a date. The recreation page link goes to the Forest Service site, which may redirect to the forest's recreation index.
Camping nearby
Campsite Atlas cards carry site counts and booking links from Recreation.gov. Forest Service cards come from the recreation layer and link the agency page.
Fire nearby
- WildfireWillow
50 mi from the trail midpoint · 7,389 acres · 80% contained
Distance is to the reported incident point, not the fire edge. Closure orders are on the forest's official page.
Explore
Historic places nearby
Reference
Questions people ask
How long is the No-See-Um Trail?
10.6 miles, the sum of the 4 segments the Forest Service records under this name in Arapaho and Roosevelt National Forests.
Source: Forest Service trail layer
What is allowed on the No-See-Um Trail?
hiking, horse and pack stock, mountain biking, motorcycle, atv, e-bikes, snowmobile, snowshoeing and cross-country skiing. The trail is open to at least one motorized use. Some uses are seasonal. The allowed uses section lists the dates.
Source: Forest Service trail layer
Where does the No-See-Um Trail start?
The line begins at 39.8937, -106.0895 and ends at 39.8937, -106.0895. No Forest Service trailhead is recorded within a third of a mile of it. The record does not say which end is the usual start.
Source: Forest Service trail layer
Is the No-See-Um Trail in a wilderness area?
No. The trail line does not cross any polygon in the National Wilderness Preservation System layer.
Source: Wilderness Connect
Where can I camp near the No-See-Um Trail?
Horseshoe Campground (0.5 mi) is within five miles of the trail. Site counts and booking links are on Campsite Atlas.
Source: Campsite Atlas
How developed is the No-See-Um Trail?
Trail class 2 to 3, which the Forest Service describes as moderately developed to developed. Class 1 is a minimal, unimproved route and class 5 is fully developed, often paved.
Source: Forest Service trail layer
How steep and how wide is the No-See-Um Trail?
The typical grade is 12-20 percent on most segments and 5-8 percent on others. The typical tread is 18-24 inches wide.
Source: Forest Service trail layer
Who manages the No-See-Um Trail?
Arapaho and Roosevelt National Forests, Forest Service unit 0210. The trail is in Colorado.
Source: Arapaho and Roosevelt National Forests official page
Is there a fire near the No-See-Um Trail?
1 active incident within 50 miles of the trail midpoint as of 2026-09-17, the nearest Willow at 50 miles. Check the forest's closure orders before you go.
Source: Fire nearby
Source
This page is built from 4 segments named NO-SEE-UM in the Forest Service TrailNFS_Publish layer, administrative unit 0210. Wilderness overlap is tested against the National Wilderness Preservation System layer from Wilderness Connect. Trailheads and Forest Service campgrounds come from the Forest Service Recreation Opportunities layer. Data refreshed September 17, 2026. The methodology page explains how segments become trails.