Longwell Peak (=Fire Peak 1203m Benchmark, near Lake Mead, NV)

pics by Harlan W. S.
Dec 21, 2008

This was an interesting little peak, if mainly from a geological perspective; else, this route is intentionally low on excitement. This trip familiarized me with a class 2 route, in case we wish to climb the peak later, then rap down the dryfalls. Thanks to Mike C and Jason for beta. John Vitz had signed in 12 days before!

This area is of great geologic interest.  The relatively young (14-16 million years) Thumb member conglomerates, derived from rapid erosion of the much older carbonate rocks (> 300 million years), filled ancient depressions.  Many of those channels were re-cut in more recent times, leaving deep canyons bordered by Thumb rocks.  Much of the initial mapping was done by Chester Longwell of the USGS.

Obviously, this hike could be fatally hot in summer, late spring, and early fall. There is no trail.

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This 100k topo shows the GPS track for this peak (red), and for the previous visit to this range (black).

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24k topo for the track.

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Geologic map with track in red.

Thtf is an exposure of the Thumb member, here present as chaotic conglomerate channel fills. The pink through purple (Op, MDs…) are Paleozoic limestones-dolostones from the chopped-up thrust sheet.

 

 

 

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On December 07, 2008, we saw Fire 1203m from the northern part of the range, and were impressed with the prominence.

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Back to Dec 21. The route starts across the desert, then heads up to a pass. No part of the route need be harder than class 2; just pick your way to cuts in the cliff bands.

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After the 1st pass, one descends N down a gully to the main canyon. This view is back ENE, after entering the main canyon.

 

 

 

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When the main canyon turns sharply left, leave the main branch and travel up behind these huge conglomerate boulders to a higher shoulder.

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This view is E toward the Gold Butte area; photo taken near the high shoulder.

 

 

 

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This view is NW from the high shoulder. Traverse along the R wall and enter a hidden slot just right of the cave. (The point of coming to the shoulder was to avoid a huge dryfall down-canyon.)

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The canyon is now narrow, but still (except for occasional climbs around catclaws) class 2.

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A view back SE from the high canyon.

 

 

 

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View ~SW, with Mount Wilson AZ in the distance.

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The high Muddy Mountains to W.

 

 

 

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Moapa Peak is on the skyline.

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The Virgin Mts are to the NE.

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A view N, showing the Valley of Fire.

 

 

 

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Descending, showing the catclaws.

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An arch, just before the traverse to the shoulder.

 

 

 

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The descent gully has this greenish sedimentary rock, an altered tuff colored by Fe(II) silicates.

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The conglomerate.

 

 

 

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A huge boulder of very coarse conglomerate. The clasts are the older limestones and dolostones.

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Water puddles, just before climbing to right out of the main channel, back to the pass.

 

 

 

Descending E off the pass.