Abineau-Bear Jaw Loop: Flagstaff Trail Guide

The Trail: What to Expect Mile by Mile

The Abineau-Bear Jaw is a lollipop loop — a stem that branches into a loop at the top. Most hikers go up the Abineau Canyon side (steeper, more dramatic) and descend the Bear Jaw side (more gradual, through open aspen meadows). The description below follows that direction.

Miles 0–0.5 (Approach): From the FR 151 trailhead parking pullout, a flat connector trail through ponderosa pine reaches the loop junction. No elevation gain here. The forest is open and cool in the morning; it warms noticeably by 10am in summer.

Miles 0.5–2.3 (Abineau Canyon — steep ascent): The trail enters Abineau Canyon and begins climbing steeply through spruce-fir forest. The canyon is narrow and shaded — conditions that keep snow lingering here into June and create dramatic ice formations in November. The grade is sustained and rocky, with exposed root systems that require careful foot placement. This is the section where altitude becomes most noticeable: if you're breathing harder than you expect for your fitness level, you're experiencing the 9,000+ ft start. Go slower, not faster. The canyon walls are close and the forest canopy is dense; you'll emerge from the trees onto an open ridge at mile 2.3.

Miles 2.3–3.2 (Ridge and high point): The trail follows the ridgeline with views west toward Hart Prairie meadow and north toward the Colorado Plateau. The high point is approximately 10,800 ft — you've gained 1,800 ft from the trailhead. The exposed ridge gets afternoon thunderstorm risk in July–August; if you see storm buildup, this is the section to move through quickly and descend.

Miles 3.2–5.0 (Bear Jaw descent — through aspens): The Bear Jaw Trail descends more gradually through one of the densest aspen groves on the San Francisco Peaks. In late September and early October, this section is the peak of fall color — gold and orange canopy above a forest floor carpeted in fallen leaves. The trail is wider and less technical than Abineau Canyon; most hikers find this the most enjoyable section despite being the longest.

Miles 5.0–5.5 (Return to trailhead): Rejoin the approach connector and return to the FR 151 trailhead.

Trailhead Access and Parking

From downtown Flagstaff, drive US-180 North approximately 17 miles. Turn right on FR 151 (Hart Prairie Road) — the turnoff is signed. Drive 1.5 miles on the maintained dirt road to the trailhead parking pullout on the right. The road is passable in a standard 2WD vehicle in dry conditions. After heavy rain or early in the season (May–June), a high-clearance vehicle is recommended. GPS: 35.3847° N, 111.7189° W.

Parking: The pullout holds 6–8 vehicles. On peak fall weekends (late September, early October), it fills by 8am. Arrive by 7:30am or plan to park on the roadside shoulder — do not block the road. There is no overflow lot. The trailhead has no facilities — no water, no restrooms, no ranger station.

Fall Color: The Best Reason to Do This Trail

The Abineau-Bear Jaw Loop has one of the highest concentrations of aspen trees of any Flagstaff-accessible trail. Peak fall color on the San Francisco Peaks typically runs September 25–October 10 depending on the year — exact timing varies by 7–10 days based on late-season rain and nighttime temperatures. The Bear Jaw descent section is the best color payoff: a north-facing slope with dense aspen that holds color longer than sun-exposed areas. For current color conditions, the Coconino National Forest district office in Flagstaff (1824 S Thompson St) posts updates, or check recent AllTrails reports with photos. For the full fall foliage picture, see our Flagstaff Fall guide.

Abineau-Bear Jaw vs. Humphreys Peak: Which Should You Do?

Both are difficult San Francisco Peaks hikes, but they're different experiences. Humphreys Peak (4.9 miles one-way, 3,300 ft gain) takes you to Arizona's highest point at 12,633 ft — above treeline, exposed, and requires fitness and altitude acclimatization. It's a longer, harder day. Abineau-Bear Jaw is a shorter loop that stays in the forest and aspen zone — more achievable in a half-day, better for dogs, and dramatically better for fall color. Choose Humphreys if summiting a state high point is the goal; choose Abineau-Bear Jaw if you want an immersive forest loop with extraordinary fall scenery. See the Humphreys Peak guide for the full comparison.