Mount Morrison from Hot Springs Creek

Looking about 6 miles (9.5 Km) south-southwest from the Hot Springs Creek area, within Long Valley Caldera, Mount Morrison is the highest peak. The route to the top follows the rolling green valley (a glacial moraine) on the far left side of the image. The starting point at Convict Lake is behind the foreground hills.

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Sevehah Cliff and Convict Lake

This is an early morning view looking west at the Sevehah Cliff rising above Convict Lake along the steep eastern side of the Sierra Nevada. The Sevehah Cliff are beds of Devonian-Age Mount Morrison Sandstone which are steeply-dipping to the east. However, these beds are overturned, as they were tilted westward over 90 degrees during a long history of folding and faulting, beginning with the Late Devonian-Early Mississippian Antler Orogeny. This view is along the path to the top of Mount Morrison. These geologic units pre-date the granitic intrusions that make up much of the high Sierras. They are typically found as roof pendants, capping the tops of ridges along some portions of the eastern Sierra Nevada. Here is a close-up of the bedding in the cliff face.

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Mount Aggie Formation

This view is looking south from the top of a glacial moraine on the east side of Mount Morrison. In the background are the steeply overturned metasedimentary rocks along a ridgeline leading north to Mount Morrison. In the foreground is a block of Cambrian- to Ordovician-age Mount Aggie Formation calcareous-silicate(?) rock. This block, which is several feet across, exhibits both tectonic folding and faulting present in the rock's source outcrop.

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Tarn Lake

A little further south, along the top of the glacial moraine, are several tarn lakes formed in depressions on the top of the moraine. The mound on the far side of the lake is part of the moraine. In the background is another view of the steeply overturned metasedimentary rocks. Mount Morrison is a little to the right of this view.

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Indian Paintbrush along the East Slope

This is a south-facing view at the beginning of the westward ascent from the tarn lake to the peak. Here was a particularly dense patch of Indian Paintbrush, a common wildflower in the high terrain of the western United States.

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East Peak

Looking north-northeast, back towards Long Valley Caldera in the background, this is the peak on the east side of Mount Morrison (seen in front of Mount Morrison in the top image on this page). The darker rocks of this peak are predominantly siliceous argillites of the Cambrian- to Ordovician-age Mount Aggie Formation.

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Midpoint up the East Slope

Looking south from about halfway up the east face of Mount Morrison, the steepness of the ridgeline becomes apparent, as does the east-dipping beds. Bear in mind that since the beds are overturned, the older rocks are on the left and the younger rocks are on the right.

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Summit View

After about 4 hours, a distance of about 5 miles (8 Km), and 4,647 feet (1,416 meters) of climbing, here is the view from the 12,268-foot (3,739-meter) peak of Mount Morrison. The lighter-colored rock at the peak (also seen in the image at the top of this page) is Devonian-age Mount Morrison Sandstone. As the morning turned to afternoon, clouds built up into scattered thundershowers, a common occurrence in the Sierra Nevada in the summertime. Looking northwest, back towards the Mammoth Mountain area, a downburst accompanied by thunder and lightning occurred. Although none were located in this trip, there are reported to be fulgurites at the top of Mount Morrison, indicative of frequent lightning strikes. With this in mind, the time spent at the peak was kept to a minimum. The east-dipping beds of the Sevehah Cliff are seen on its side from the peak. The set of jagged peaks seen on the left in the background is the Minaret.

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