The Alluvial Fan Trail in Rocky Mountain National Park is a relatively short and accessible trail that provides an up-close view of the Alluvial Fan.
Alluvial Fan Trail Basics
Under 1 Hour
0.7 Miles Round Trip
Out-And-Back
82 Feet
Duration: Under 1 Hour
Walking along the Alluvial Fan Trail takes under one hour, even if you are taking your time to enjoy the views on the path.
Distance: 0.7 Miles Roundtrip
There are two trailheads for this trail, and to walk between the west lot and the east lot, the entirety of the trail is 0.7 miles roundtrip.
Type: Out-and-Back Trail
The trail goes between two main parking areas so it’s considered an out-and-back trail.
Elevation Change: 82 Feet
There is one small spot, about 75 feet in length, of a steep grade, but the rest of the trail is relatively flat.
Season: Spring, Summer, Fall
During the winter months, when there’s heavy snowfall, the roads and trails may be inaccessible. Most of the time, snowfall starts in late September or early October and continues through late May or early June.
Due to the threat of snow, ice, and closures, the best time of year to go to Rocky Mountain National Park and walk on the Alluvial Fan Trail to see this natural phenomenon is from mid-June through early September. Even then, dress in layers so you can be ready for any weather conditions.
Time of Day: Any
Rocky Mountain National Park is one of the most visited parks in the United States, so it’s always best if you can arrive early before the parking areas fill up. Rocky Mountain also operates on a timed-entry reservation, so keep that in mind as you make your plans for the day. You can also enter before the timed permit starts or do an end of day hike by coming in after the timed entry finishes for the day.
Amount of Shade: Minimal
There is very little shade on the Alluvial Fan Trail. A few trees dot the sides of this short trail, but not enough to give adequate coverage.
Difficulty: Easy
Alluvial Fan Trail is a very easy trail for hikers of all abilities to enjoy. It is on a paved path with a very short distance and little elevation gain.
What Makes Alluvial Fan Trail a Great Hike?
The Alluvial Fan area was formed by debris flow from a major flood event in 1982 after a significant rainstorm hit the area. The flow of water, rock, and sediment came down the slope of the mountains as a result of the Lawn Lake Dam break and spread out in a fan shape at the base of Fan Mountain. The Lawn Lake Dam was an Earthen dam, so all of that debris rushed downstream to create an interesting spectacle. This reshaped the landscape and created a distinctive landform from the wall of water rushing through.
It’s amazing to see the power that millions of gallons of water have over the landscape. This popular visitor attraction walks along the boulder field on an asphalt trail to get a close-up view of the debris from the great Lawn Lake floods and Horseshoe Falls upstream on the Roaring River.
Because of all of the boulders, this was a great spot to start our first day in Rocky Mountain National Park. The boys love to climb on boulders, so they were constantly going along the side of the trail to climb the large boulders rather than walk the paved trail surface.
We started on the east side of the trail and walked across the pedestrian bridge, past the beautiful cascade of water, to the west parking area. There we turned around and went back to the east parking spaces and our rental car.
Scenery on the Alluvial Fan Trail
Start of the Trail
Whether you start the trail from the west end of the trail or the east end of the trail, you will be walking in an open area among giant car-sized boulders.
On the Trail
About halfway up the trial, you’ll come to the 56-foot bridge that crosses the Roaring River. Here you can see the results of the natural phenomena that can occur from a flooded river.
End of the Trail
The trail ends at the other parking area. Most people will turn around when they reach the bridge crossing, though, since the trail is similar on both sides of the new bridge.
Notable Places on the Hike
Per a park ranger’s recommendation, visit the area in the fall. The aspen groves in Endovalley have some of the most dramatic fall foliage in the park.
Alluvial Fan Trailhead Information
Park Name: Rocky Mountain National Park
Rocky Mountain National Park is in the north-central area of Colorado in the United States. It is bordered by the town of Estes Park on the east and Grand Lake to the southwest. The park is about 55 miles north of Denver with Denver International Airport (DEN) being the closest major airport.
During peak season, from the end of May through mid-October, the park uses a timed entry reservation system. Every vehicle entering the park has to have a permit in addition to paying their entry fees. It's a good idea to get a permit as soon as they open for the season. To go to Alluvial Fan Trail, you'll need the regular entry permit (not one with Bear Lake unless you plan to go there, too). Otherwise, you can enter the park before 9 AM or after 2 PM.
Finding the Trailhead
If you park in the west lot, the trailhead will be to your east. If you park in the east parking lot, the trailhead will be to the west. The Alluvial Fan Trail goes between the two parking areas.
Markers Along the Trail
While on the trail, there are a few interpretive signs that explain the formation of the site. You can also learn about the major trail work that the National Park Service did on the trail in 2020. The new trail was part of the Centennial Challenge Program to restore and repair miles of trails throughout the country's national parks. This included the construction of the new accessible pedestrian trail at Alluvial Fan.
Nearest Restrooms: West Parking Lot
There is a vault toilet located in the west Alluvial Fan parking areas. One is not available in the east parking lot.
Parking Area
There are two parking lots for the Alluvial Fan Trail because the trail meanders between the two. Both lots can be accessed on Endovalley Road, sometimes called Old Fall River Road, near Horseshoe Park. If you are coming from the Fall River Entrance, drive a few miles up Trail Ridge Road until you see the signs for Endovalley and Old Fall River Road on the right. Otherwise, if you are coming from the west side of the park, turn left at Deer Ridge Junction then left onto Endovalley Road. Those entering from the Beaver Meadows Entrance Station will follow the road to Deer Ridge Junction and turn right onto Highway 34 then left onto Endovalley Road.
The west parking lot is about 0.8 miles from the intersection of Endovalley Road and Trail Ridge Road. The east parking lot is 0.5 miles from the junction. Both parking areas will be on the right side as you drive into Endovalley.
Other Trails at this Trailhead
Nearby you can find the Lawn Lake Trailhead which is a difficult trail that winds 6.2 miles through the heart of the Mummy Range up to Lawn Lake. All-in, this is a 12.4-mile round trip out-and-back trail.
The Lawn Lake Trail also intersects with a side trail to Ypsilon Lake which is 4.5 miles one-way from the junction with Lawn Lake Trail.
Tips for Alluvial Fan Trail
- Bring a picnic lunch to enjoy at the Endovalley picnic area at the end of the road.
- You can scramble up the giant boulders to get to Horseshoe Falls.
- After finishing at the Alluvial Fan, continue up the one-way Old Fall River Road to the Alpine Visitor Center to go to the highest visitor center in the National Park System.
Accessibility Information for Alluvial Fan Trail
Paved Gravel
Paved
Trail Type: Paved Gravel
The trail has a few accessible features that were implemented as part of the Centennial Challenge. Only one of the small trail sections has a steep grade, but the rest of the trail is on flatter land with paved gravel pathways. To avoid the 19% grade, park in the west parking area and go to the bridge then back. The steep grade is between the east parking lot and the bridge. The bridge is a well-built wooden bridge, making it one of the best places for those with mobility issues to see the beauty of the park.
Parking: Paved
Both of the parking lots are paved with a few designated handicap parking spots.