Stage 1 fire restrictions, enacted for unincorporated areas of western Boulder County.

Anne U. White Trail
Anne U. White Trail

Anne U. White Trail

The parking lot and trail will be closed on Wednesday, July 17, for restroom installation. A crane will be used and will prevent access to the trail.

The popular 1.7-mile, pedestrian-only trail crisscrosses Four Mile Canyon Creek through a narrow canyon of lush vegetation and varied wildlife habitat.


  • Anne U. White Trail
    1.7 miles – Moderate
    Hiking Allowed Dogs Allowed Bikes Prohibited E-bikes Prohibited Horses Prohibited

Rules & Regulations

Day Use Only
Pets On Leash
No Bikes
No Open Fires
No Hunting/Firearms
No Camping

All Parks & Open Space Regulations

Trailhead Amenities

28 car parking spots
1 ADA parking spot
Portable toilet near trailhead

Keep In Mind

  • The Anne U. White Trail follows the Fourmile Canyon Creek and crosses the creek numerous times.
  • Bikes and horses are not allowed.
  • Limited street parking in designated areas only. Please respect the neighbors.



  • American robin
  • Black-billed magpie
  • Broad-tailed hummingbird
  • Cooper’s hawk
  • Cordilleran flycatcher
  • Lesser goldfinch
  • Mountain chickadee
  • Northern flicker
  • Pygmy nuthatch
  • Red-breasted nuthatch
  • Steller’s jay
  • Tree swallow
  • Violet-green swallow
  • White-breasted nuthatch
  • Wild turkey


  • Abert’s Squirrel
  • Golden-mantled ground squirrel
  • Least chipmunk
  • Mule deer
  • Mountain lions
  • Pine squirrel
  • Yellow-bellied marmot

Reptiles & Amphibians

  • Bullsnake
  • Prairie lizard
  • Wandering garter snake

Insects & Other Invertebrates

  • American lady butterfly
  • Blue and copper butterfly species
  • Blue fungus beetle
  • Cicada
  • Common water strider
  • Damselfly species
  • Fritillary butterfly species
  • Hoary comma
  • Hunt’s bumblebee
  • Long-jawed orb weaver spider
  • Mourning cloak butterfly
  • Pacuvius duskywing
  • Skipper butterfly species
  • Twelve-spotted skimmer dragonfly
  • Weidemeyer’s admiral


  • Aspen
  • Douglas fir
  • Eastern cottonwood
  • Narrowleaf cottonwood
  • Ponderosa pine


  • Red-osier dogwood
  • Smooth sumac
  • Skunkbush sumac
  • Waxflower
  • Wax currant
  • Wild rose

Blue/Purple/Magenta Wildflowers

  • Bee balm (Monarda fistulosa)
  • Fireweed (Chamaenerion angustifolium)
  • Larkspur (Deliphinium sp)
  • Low penstemon (Penstemon virens)
  • Pasqueflower (Pulsatilla patens)
  • Rocky mountain bee plant (Cleome serrulata)
  • Sidebells penstemon (Penstemon secundiflorus)
  • Western spiderwort (Tradescantia occidentalis)
  • Prairie Bluebells (Mertensia lanceolata)

Yellow Wildflowers

  • Blanket flower (Gaillardia aristata)
  • Curlycup gumweed (Grindelia squarrosa)
  • Ground cherry (Physalis sp)
  • Oregon grape (Berberis repens)
  • Wild buckwheat (Eriogonum sp)

White/Light Pink Wildflowers

  • Canadian milkvetch (Astragalus canadensis)
  • Mariposa lily (Calochortus sp)
  • Prickly poppy (Argemone polyanthemos)
  • Rough-fruited fairybells (Prosartes trachycarpa)
  • Spreading dogbane (Apocynum androsaemifolium)
  • Star-flowered lily-of-the-valley (Maianthemum stellatum)
  • Western Solomon’s plume (Maianthemum racemosum)
  • Western springbeauty (Claytonia rosea)
  • Wild geranium (Geranium sp)
  • Smooth blue aster (Symphyotrichum laeve)
  • Yarrow (Achillea sp)

The canyon and creek had long been used by locals, so when a development plan for the area was announced in 1983, public outcry to save the corridor was strong. In response, Boulder County purchased easements and property to preserve the canyon for wildlife and public access.

Gilbert and Anne U. White donated a portion of land to Boulder County that was key to the success of the trail. Gilbert White is known for his contributions to floodplain management, especially around Boulder Creek, and Anne U. White, for whom the trail was named, served as an early member of the Parks & Open Space Advisory Committee.

Like many properties in the area, Anne U. White was damaged in the 2013 Flood. The trail remained closed for restoration and trail construction until December of 2019, and in some places, looks quite different than it used to.

Management Plan Amended

On Dec. 13, 2018, the Board of County Commissioners approved an amendment to the Fourmile Canyon Creek Park Management Plan to allow for expansion of the parking area that incorporates the following considerations:

  • Parking capacity may be expanded to accommodate up to 30 vehicles (at least 15 to 20 vehicles seem feasible).
  • Flood resilience should be a significant component of the design (e.g., 100-year flood design, boulder toe wall, etc.).
  • Stream restoration is an important component of the project. Consideration should be given to supporting montane riparian ecosystem functions in the overall design.
  • A permanent restroom facility may be constructed assuming a suitable location can be permitted.
  • The Anne U. White Trail shall be designated for pedestrian use only.
  • A plan for managing parking and other safety and enforcement concerns on Wagonwheel Gap Road during periods of high visitation shall be developed in coordination with the Transportation Department, law enforcement, the local fire district, and neighboring land owners prior to reopening the trail.

Contact Us

Parks & Open Space

8 a.m. to 4:30 p.m.

Office Location

5201 St. Vrain Road
Longmont, CO 80503
Map and Directions
Office Hours: 8 a.m. to 4:30 p.m.
Friday by phone, email, or appointment only.

Parks are open sunrise to sunset