Hewlett Gulch trail is located 22 miles northwest of Fort Collins, Colorado in the Poudre River Canyon. Specifically, it is 10.5 miles west of the CO-14 and US-287 intersection and on the right side of CO-14 with the trail head on the other side of a bridge. Primary outdoor activities at Hewlett Gulch trail include mountain biking and hiking with dogs. The limited change in elevation is conducive to hiking with kids but the many stream crossings should be considered. Parking is free and includes enough space for a horse trailer but space can be limited on a busy day. The trail head includes restrooms but no water and limited cell phone service. Other hiking trails in the Poudre River Canyon include Seaman Reservoir Trail, Gateway Natural Area, Greyrock Mountain Trail, and Young Gulch. Young Gulch mountain biking is similar but more difficult than Hewlett Gulch mountain biking.

Hewlett Gulch trail is maintained by the Arapaho & Roosevelt National Forests. It is 3.0 miles one way with a mild elevation gain from 5,600 feet to 6,200 feet. The main trail follows Gordon Creek until it reaches private property. However, there is an additional loop trail that provides additional hiking and mountain biking. The following picture shows the beginning of the trail.
The trail crosses Gordon Creek numerous times so mountain bikers should be prepared to get wet and hikers to carefully navigate some of the wider crossings.
Although numerous, the stream crossings are narrow and shallow (i.e., less than a foot deep) which is advantageous for both mountain bikers and dogs.
Some of the stream crossings are rocky enough to provide technical challenges to mountain bikers but should pose few problems to hikers.
The following picture illustrates an intersection where the main trail stays to the right and the additional loop trail bears left. The additional loop trail reconnects to the main trail at the end of the main trail. Hikers can have an enjoyable experience hiking the loop in either direction. However, turning left at this intersection means that mountain bikers will experience a long, steep, and rugged climb. Thus, I recommend mountain bikers continue on the main trail and connect to the loop at the end of the main trail.
Hewlett Gulch trail consists of an interesting dichotomy between rocky stream crossings and smooth, narrow single track trail.
What’s more, there were several sections where the brush had grown across the trail and was providing resistance that made it tough to bike through. The trail head warns that in the late spring and summer, wood ticks can be found near brushy areas so bug repellent is recommended.
Traveling farther on the trail offers more scenic views and a healthy mix of sun and shade. Colorado Black Bears can be found foraging near the trail during their fall feeding frenzy. In addition, mountain lions can be present but are rarely seen.
The following picture shows the start of a long climb and represents the end of the main trail. Up to this point, the elevation gain has been unnoticeable. Turning around here makes for an easy mountain bike ride back to the parking lot. However, continuing on the additional loop trail results in a commitment to bike on a steeper and significantly more rugged trail.

The additional unnamed loop trail is a continuation of the main trail, 2.6 miles long, and climbs 600 feet to 6,800 feet in elevation. The additional loop rides west and then descends south to the main trail. Specifically, it connects to the main trail 2.0 miles from the trail head so the main trail plus loop trail totals 7.6 miles.
The set of initial climbs and descents on the loop are long, challenging climbs on smooth, single track.
The following panoramic picture highlights the view experienced from climbing up the initial hill.
The trail continues to climb and its smooth single track reminds me of Blue Sky Mountain Bike Trail in Horsetooth Mountain Park.

From here, the ruggedness increases and the trail drops down into a little valley before the final descent.

On the last half of the loop, the landscape opens up with a view to the west.

Although the following picture does not do it justice, the next section of trail is a sheer drop followed by a steep climb. My plan was to ride down the sheer drop and have a soft landing in the snow on the other side. Unfortunately, I crashed my mountain bike at the bottom of the hill and probably at the point where I had the most momentum. My right shoulder absorbed most of the impact and was still sore a month later. I attribute some of my fall to my skills but mostly to the muddy conditions because my bike slipped out from under me and sent me flying 5-6 feet away. This crash was another instance where I was glad I was wearing a mountain bike helmet and carrying a first aid kit with ibuprofen. After climbing the hill on the other side the trail makes a 90 degree left turn.

After crossing over the top of another ridge, the trail begins a prolonged descent that is very rocky. It is this final stretch on the loop that is the basis for my recommendation to do this loop in a counter-clockwise direction. My cantilever brake pads were not sufficient enough to make it down without walking some of the way.

On the final descent towards the main trail I spotted a True Mountain Mahogany seed that was going against all odds by germinating in the middle of the trail. In addition, Fringed Sage, Rubber Rabbitbrush, and Rocky Mountain Ponderosa Pine can be found near the trail.

In sum, Hewlett Gulch trail is an easy hike that is well suited for dogs. For mountain bikers, the trail is a fun single track that offers stream crossings and a mix of smooth and rugged stretches. The additional unnamed loop is a significantly more difficult ride that requires more energy and technical skills. Read my list of Colorado mountain bike trails for more fun along the northern front range.