Sedona Trackers Group Explore Red Mountain: A Magical Place

December 08, 2023

By Jon Petrescu

An unusual maze of hoodoo formations can be found in the amphitheater of the Red Mountain Trail north of Flagstaff. These eerie spires were formed as the volcanic cap rock eroded in the years since the last volcanic eruption.

The Trackers group of the Sedona Westerners hiking group recently visited Red Mountain in the Coconino National Forest. This hike was led by Ernie and Lynn Pratt.

This was a more intense geological learning experience than just a hike in the woods. Red Mountain is a site that most people drive past without stopping in their rush to get to the Grand Canyon. It is located at mile marker 247 on Highway 180 twenty-eight miles north of the Museum of Northern Arizona – under a 2-hour drive from Sedona. 

We spent a little over three hours learning about – and scrambling through – the volcanic amphitheater that is all that remains from the 740,000-year-ago eruption, and then the explosion, near the base of the cinder cone. Now, due to its bright color, it is called Red Mountain. Cinder cones, Ernie explained, usually only take a year or so to form.

At an elevation of 7,800 feet, it was cool, and initially, we required an outer layer to stay warm. From the trailhead parking area, we followed a wide trail through a Juniper/Pine Forest. At several stops along the way, Ernie and Lynn described the geologic history of what had taken place and pointed out different types of rocks that were ejected or that had flowed as lava from Red Mountain. 

We learned about the different types of volcanoes, the four volcanic fields around the Sedona and Flagstaff area, and – due to Continental Drift – that sometime in the future the area east of Flagstaff will experience another volcanic eruption. The most recent eruption was the one that created Sunset Crater less than 1,000 years ago.

After about three-quarters of a mile the life zone transitioned from the Juniper/Pine Forest to a Ponderosa Forest. Shortly thereafter we came to our first surprise. Red Mountain was going to make us work to get into its interior. 

A wooden ladder stood before us that we needed to climb to access the amphitheater. It was either that or struggle up the loose lapilli. Lapilli are droplets of molten lava ejected from a volcanic eruption that falls to earth while still at least partially molten. Trying to climb up a hillside surface of lapilli is virtually impossible. With almost every step you slide back almost that entire step. We all opted to climb the ladder.

The real surprise was revealed when we arrived at the amphitheater. Before us was an eerie, hoodoo-filled topography. This was not the main caldera but a side blowout near the base of Red Mountain. Ernie explained that early cementation of the lapilli layers occurred trapping surface water. Pressure built up and eventually caused a massive steam-assisted blowout. Geologists call these phreatic explosions.

Before exploring the amphitheater, Ernie described the process which caused hoodoos to be formed. We learned these spires are formed when the softer material below the harder volcanic cap rock (bomb) is eroded by water and wind. This softer material is comprised of lapilli cemented together by calcareous cement and a mixture of volcanic ash and water. 

We took our lunch break in front of the amphitheater. After lunch, Ernie and Lynn displayed several volcanic-created rocks of different types and described how each type was formed. We then walked a couple of the trails through the maze of hoodoos. You can’t get lost on these short trails. They all end after about a hundred feet. 

We all enjoyed the geology lessons and hike. While walking out we shared with each other the different experiences we had. 

Trackers hikes are special interest hikes organized by the Sedona Westerners. These hikes were established in 2005 and are now held on selective Wednesdays. Past hike topics include archeology, botany, ethnobotany, geology, and photography. Some of the Trackers outings can be described as field trips, while others will be hikes or rock scrambles. The Westerners have seven more Trackers events scheduled this season involving archeology, edible and medicinal plants, and the Native American Heritage Trail and Garden tour to name a few.

To learn more about the Trackers and the Sedona Westerners Hiking Club, to view this season’s hiking schedule, or to become a member go to The hiking season runs through May 9, 2024, and the membership fee is only $30 for the whole season.

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