A'a Trail Loop

Sunset Crater Volcano National Monument, Arizona

Trip Date: Thursday, July 25th, 2019
Last Updated: Wednesday, February 5th, 2020
By Ricky Holzer

Hike Information

Rating ★★★☆☆(3/5)
Overall Difficulty Easy
Navigation Difficulty     Easy
Distance 0.2 miles roundtrip
Time 15 minutes
Terrain Mostly flat
Best Seasons All
Family Friendly Yes
Dog Friendly No
Accessible No


Hike Summary

The Hawaiian word "a'a" (pronounced ah ah) is a common descriptor for lava flows worldwide, characterizing lava with a high volume and velocity that cools into rough formations. Throughout your hike on the A'a Trail, you will witness this term firsthand as you observe the jagged basalt formations of the Bonito Lava Flow.

The trail forms a short loop, and which direction you go depends mainly on where you parked. Just follow the well-defined trail closest to you. Looking to the east, you'll see Sunset Crater rising above the lava flow, as pictured below. Nearly 1000 years ago, this now extinct volcano erupted and created the field of dark rock where you stand. Fun fact: Sunset Crater was the last volcano to erupt in Arizona.

Sunset Crater peeking over the hill

Sunset Crater peeking over the hill

To the northwest, you can see another extinct volcano named O'Leary Peak, pictured below. This mountain rises to almost 9,000 feet in elevation, and its black surface was caused by Sunset Crater spraying lava. If you're interested in a challenge and some great Northern Arizona views, you can hike up the forest road leading to the top of O'Leary Peak.
O'Leary Peak in the distance above the lava flow

O'Leary Peak in the distance above the lava flow

Notice how some hardy shrubs and trees grow directly on top of the solid rock surface, as pictured below. The volcanic ash made the underlying soil in the area more fertile, which is one reason Native Americans populated nearby Wupatki Pueblo in the desert to the north of here.
The jagged basalt formations of the Bonito Lava Flow

The jagged basalt formations of the Bonito Lava Flow

Though the trail is short, it's a cool place where you can learn about geology. Connect with me using the social media links below and share your adventures!

Important Information

Dogs are not allowed on any trails in the park; it's best to leave your dog at home since desert temperatures can kill dogs waiting in cars. This hike is great for families since it is so short. You can visit during any season, but be prepared for wind. In the summer, temperatures can exceed 100 degrees and afternoon thunderstorms are common. Winter and early spring may bring snow, but it doesn't usually stick around long. Expect to see people, especially on the weekends.


From Flagstaff, take Interstate 40 east. Take the exit for U.S. Highway 89, then turn left. Turn right onto U.S. Highway 89. Turn right at the brown sign pointing to Sunset Crater Volcano National Monument and Wupatki National Monument. After passing the visitor center, look for a small parking area on the left hand side of the road. If this lot is full, continue straight then take the first right into the parking area for the Lava Flow Trail -- you'll have to take a short spur trail to reach the A'a Trail.

Google Maps Directions

Parking, Fees, and Facilities

Entrance to the park is $25 per vehicle and permits access for 7 days to both Wupatki National Monument and Sunset Crater Volcano National Monument. Interagency passes are also honored here. Visit the park's fees page for more information. There are no facilities at the trailhead, but there are pit toilets at the nearby parking for the Lava Flow Trail. Otherwise, the staffed visitor center has restrooms and water in addition to educational exhibits and a gift shop.

Nearby Hikes

The San Francisco Peaks looming high in the distance
Lenox Crater Trail Loop
Sunset Crater Volcano National Monument, Arizona
The paved trail to the Bonito Lava Flow
Bonito View Trail
Sunset Crater Volcano National Monument, Arizona
Looking south towards Agassiz and Fremont Peaks from the top of one false summit
Humphreys Peak (Arizona State Highpoint) via the Humphreys Peak Trail
Coconino National Forest, Arizona
Doney Mountain with the San Francisco Peaks in the background
Doney Mountain
Coconino National Forest, Arizona

External Links