SLATE MOUNTAIN TRAIL #128

SLATE MOUNTAIN TRAIL #128

View of San Francisco Volcanic Field from Slate Mountain

There are a couple of curious things about Slate Mountain. First off, there’s no slate and second, the mountain is much bigger than it appears.

Stansbury cliff-rose shrubs grow to 8 feet high

Part laccolith (a mushroom-shaped blob of magma that formed underground) and part volcano (you know: BOOM), the 8215-foot mountain measures only 853 feet from its base to summit, but geologists estimate that the lava dome that makes up the mountain extends to 5000 feet below the surface.

Cliff-rose scents the trail

So, all things considered, Slate Mountain is a considerable beast. The complicated hill is composed mostly of a pinkish-gray igneous rock called rhyolite which is exposed along its flanks.

Heading up the trail

Kendrick Peak

The “slate” misnomer comes from the flaky appearance of some of the sedimentary and igneous rocks that were contorted during the mountain’s eruptive phase that occurred between 1.5 and 1.9 million years ago.

The "slate" is actually rhyolite 

True slate is a metamorphic stone not found in the area. The trail that climbs to the summit of this unassuming little mound north of Flagstaff doles out gratifying treats at a leisurely, constant pace. One of the first points of interest visible from the trail is the scar from the June 2017 Boundary Fire that swept up 10,418-foot Kendrick Peak. The lightning-caused blaze burned more than 17,000 acres, stopping just short of the Slate Mountain trailhead.

Near the top, the trail makes a sharp swing around the high point for a 360-degree visual smorgasbord. To the north, the San Francisco Volcanic Field rolls out over colorful plains dotted with hundreds of cinder cones and eroding craters. This arc of volcanism stretches from Williams to the area around Sunset Crater. Geologist say this hot spot is still active and predict the next eruption will occur near the Little Colorado River.

It could be years, decades or centuries before the next magma breaks the surface, so until then, the summit of Slate Mountain is a great place to contemplate the emergence of a new volcano amidst the quiet beauty of the Painted Desert, the South Rim of the Grand Canyon and the hazy silhouettes of the Hopi Buttes. 

LENGTH: 5 miles roundtrip

RATING: moderate

ELEVATION: 7360’ – 8215’

GETTING THERE:

From Flagstaff go 26 miles north on US 180 to Forest Road 191 located just past milepost 242.

Turn left and continue 1.9 miles to the signed junction for Slate Mountain, turn right and go 0.3 mile to the trailhead. Forest Roads are rough dirt and gravel. High clearance vehicles recommended. Mat be impassable in wet conditions.

INFO & MAP:

https://www.fs.usda.gov/recarea/coconino/recarea/?recid=55180