KEY INFO
LOCATION Marshall Lake to I-40
DISTANCE 18.5 miles one-way
DAY-TRIP OPTION See turnaround note in the trail description.
SHUTTLE RECOMMENDATION FR 301 (passage mile 7.2) or Walnut Canyon Road (passage mile 16.1)
DIFFICULTY Easy
LAND MANAGER Coconino National Forest, Flagstaff Ranger District, www.fs.usda.gov/coconino, 928-527-3600
RECOMMENDED MONTHS April–October
GATEWAY COMMUNITY See Flagstaff.
GEOLOGY HIGHLIGHTS Not applicable
This passage’s peaceful traverse of Anderson Mesa from Marshall Lake and along Walnut Canyon belies its proximity to the city of Flagstaff. In the bottom of Sandy’s Canyon, before the Arizona National Scenic Trail (AZT) ascends to the Fisher Point area, you will come to a junction. The left fork, a resupply route for thru-hikers, heads north into Flagstaff (see Passage 33). The right fork takes Passage 31 northeast and follows the edge of Walnut Canyon after passing Fisher Point (a popular destination for Flagstaff locals). The latter is also the equestrian bypass around Flagstaff.
A large steel AZT sign marks the singletrack departure point from the trailhead that lies southwest of Marshall Lake (7,122 feet). The trail passes through a pleasant, flat woodland of ponderosa pine and oak. At mile 1.2, the trail begins a short descent into a canyon, and then it heads west and crosses a forest road to climb the other side of this small canyon. The AZT crosses FR 128B at mile 4.0 before it descends steeply into lower Walnut Canyon. In the bottom of the canyon at mile 5.5 is the intersection with Sandy’s Canyon Trail; you can turn left to reach Canyon Vista Campground, or you can stay on the AZT and continue toward Fisher Point. The trail forks at mile 6.4. The left fork is Passage 33, the resupply route through Flagstaff. Passage 31 takes the right fork and ascends out of the canyon to Fisher Point.
TURNAROUND NOTE: A magical spot among the pines, Fisher Point makes for a pleasant destination if you’re doing an out-and-back hike for the day.
To continue along the AZT, skirt the edge of the canyon and pass a trail junction with the FR 301 trailhead. At about mile 12.2 the trail makes a steep descent into and out of a branch of Walnut Canyon. A major Arizona Trail trailhead is located on FR 303, the Old Walnut Canyon Road. After you cross Old Walnut Canyon Road, the trail gradually transitions from a ponderosa pine forest to a piñon–juniper forest. The trail crosses the paved Walnut Canyon National Monument entry road and continues east before turning north to cross under the I-40 at Cosnino Road, where Passage 31 ends. An excursion along this passage wouldn’t be complete without a side trip to Walnut Canyon National Monument, where 25 cliff dwelling rooms of the Sinagua people are well preserved within their natural surroundings.
Fires are necessary to maintain the health of the pine forests of northern Arizona, and both controlled burns and wildfires are common.
Anderson Mesa is rocky but relatively level singletrack until you drop into Walnut Canyon. There are several climbs into and out of canyons where you might need to walk your bike. The northern half of the passage is smooth singletrack through the forest and along the rim of Walnut Canyon with one 250-foot descent into a branch of Walnut Canyon. For more information about mountain biking along the Arizona National Scenic Trail, visit aztrail.org.
From Flagstaff, take the Lake Mary Road (FH 3) exit (339) off I-17 for 9 miles, and turn left (east) on FR 128 at the sign for Marshall Lake. Pass the observatory turnoff. At 2.2 miles, turn left before Marshall Lake (7,136 feet), and park at the AZT sign on the left. If you’re coming from the south on Lake Mary Road, the Marshall Lake turnoff is 7.5 miles north of Pine Grove Campground.
From Flagstaff, take I-40 east to Exit 205. Go south on the access road to Walnut Canyon Monument. Near the entrance is a junction with FR 303 and a sign to the AZT. Old Walnut Canyon Trailhead, which has room for horse trailers, is about 1.75 miles west on the left (south) side of FR 303.
Just north of Canyon Vista Campground, turn onto FR 9478Y and continue 0.25 mile to a parking area. From there it’s a short walk to a trail marked ACCESS TO ARIZONA TRAIL.
Heading east from Flagstaff, turn right off I-40 at Cosnino Road (Exit 207), and take the next right onto the frontage road (Old Route 66). There is no official parking area; however, there is space to park along the frontage road.
Marshall Lake, near the beginning of Passage 31