Entrance to the cave
|Location||Siskiyou County, California, United States|
|Length||0.5 to 1 mile (0.80 to 1.61 km)|
Pluto's Cave (or Pluto Cave) is a partially collapsed lava tube on the northern outskirts of Mount Shasta. Its main entrance is located close to the 99-97 Cutoff c. 12 miles (19 km) North-east of Weed and c. 14 miles (23 km) East-southeast of Grenada. The tube is roughly 190,000 years old, which is quite old for a lava tube, as they normally collapse quickly (in geological terms), having ceilings only a few metres thick. However, Pluto's Cave is located in a semi-arid climate, where erosion is restricted, which contributes to its survival.
The cave was discovered in the spring of 1863 by Nelson Cash, who came upon it while looking for stray cattle. It was further explored in April 1863, and named "Pluto's Cave" after Pluto, the Greek God of the underworld.
William Henry Brewer assisted by Clarence King on a field trip for the California Division of Mines and Geology (predecessor of today's California Geological Survey), visited the cave on October 10, 1863. Brewer writes about it a month later on November 11:
October 10 in the morning we went to visit a cave about three-quarters of a mile distant, just discovered, and of which extraordinary stories were told. It was, indeed, quite a curiosity. It is called Pluto’s Cave. The surface of the country is a gentle lava slope, very rocky, with but little soil and with stunted cedars and bushes, the lava rising into innumerable hummocks a few feet high. Under this the cave extends. It looks as if the surface of the great lava flow had cooled, but that the crust had broken somewhere lower down and a long stream of the fluid had run out, leaving a long, empty channel or gallery. The roof of this gallery is beautifully arched—in places it is at least fifty feet high and as many broad. The bottom is of broken blocks of lava, and the sides are occasionally ornamented with fantastic shapes of stone, where the melted or viscous fluid has oozed through cracks, sometimes in a thick, black stream, like tar, then cooled, in others like froth on the surface of the molten mass—but all now cool enough, hard, rough, black rock. We went in near a mile, to the end, or at least to where the fallen fragments blocked up the way. Multitudes of bats lived in it, even to the very end. Near the entrance the roof had broken in in several places, and there were many skulls of mountain sheep that had got in and perished. These are the chamois of the Rocky Mountains and Sierra. They are nearer a goat than sheep, and have enormous horns, hence some hunters call them the "big horn." On one of these skulls the horns were 14 1/2 inches in circumference at the base and 33 inches between the tips.— William Henry Brewer, "Book 4, Chapter 7", Up and Down California in 1860–1864 (1930)
King in 1870, now a director of the Geological Exploration of the Fortieth Parallel, returned to Mount Shasta, and with a fellow explorer revisited the cave, which King recounts in his 1872 book Mountaineering in the Sierra Nevada:
In 1863, in company with Professor Brewer, I visited this very region, and we were then shown an interesting tubular cavern lying directly under the surface of a lava plain.
Mr. Palmer and I revisited the spot, and, having tied our mules, descended through a circular hole to the cavern's mouth. An archway of black lava sixty feet wide by eighty high, with a floor of lava sand and rough boulders, led under the basalt in a northerly direction, preserving an incline not more than the gentle slope of the country. Our roof overhead could hardly have been more than twenty or thirty feet thick. We followed the cavern, which was a comparatively regular tube, for half or three quarters of a mile. Now and then the roof would open up in larger chambers, and the floor be cumbered with huge piles of lava, over which we scrambled, sometimes nearly reaching the ceiling. Fresh lava-froth and smooth blister-holes lined the sides. Innumerable bats and owls on silent wing floated by our candles, fanning an air singularly still and dense.
After a cautious scramble over a long pile of immense basalt blocks, we came to the end of the cave, and sat down upon piles of debris. We then repeated an experiment, formerly made by Brewer and myself, of blowing out our candle to observe the intense darkness, then firing a pistol that we might hear its dull, muffled explosion.The formation of this cave, as explained in Professor Whitney's Geological Report, is this: A basalt stream, flowing down from Shasta, cooled and hardened upon the surface, while within the mass remained molten and fluid. From simple pressure the lava burst out at the lower end, and flowing forth left an empty tube. Wonderfully fresh and recent the whole confused rock-walls appeared, and we felt, as we walked and climbed back to the opening and to daylight, as if we had been allowed to travel back into the volcano age.— Clarence King, "Shasta Flanks", Mountaineering in the Sierra Nevada (1872)
Regaining the low ground at the base of the mountain and holding on in your grand orbit, you pass through a belt of juniper woods, called "The Cedars," to Sheep Rock at the foot of the Shasta Pass. Here you strike the old emigrant road, which leads over the low divide to the eastern slopes of the mountain. In a north-northwesterly direction from the foot of the pass you may chance to find Pluto's Cave, already mentioned; but it is not easily found, since its several mouths are on a level with the general surface of the ground, and have been made simply by the falling-in of portions of the roof. Far the most beautiful and richly furnished of the mountain caves of California occur in a thick belt of metamorphic limestone that is pretty generally developed along the western flank of the Sierra from the McCloud River to the Kaweah, a distance of nearly four hundred miles. These volcanic caves are not wanting in interest, and it is well to light a pitch pine torch and take a walk in these dark ways of the underworld whenever opportunity offers, if for no other reason to see with new appreciation on returning to the sunshine the beauties that lie so thick about us.— John Muir, "Shasta Rambles and Modoc Memories", Picturesque California and the Region West of the Rocky Mountains, from Alaska to Mexico (1888)
- Sciences, California Academy of (1954). Pacific Discovery. California Academy of Sciences. p. 32. Retrieved February 10, 2018.
Its single unbranching passage is generally of uniform diameter throughout its extent, and is fringed with the hardened stalactitic drippings which bear evidence of the rapid disgorging of lava that once took place. Such tubes are often of great length — John Muir describes Pluto's Cave in northern California as penetrating its basalt bed for a mile.
- Selters, A.; Zanger, M. (2006). The Mt. Shasta Book: A Guide to Hiking, Climbing, Skiing, and Exploring the Mountain and Surrounding Area. Wilderness Press. p. 62. ISBN 978-0-89997-562-7. Retrieved February 10, 2018.
A number of lava tubes are found around Shasta, some of which are a mile or more long, and the most famous is Pluto Cave. Venturing into this large cave should not be taken lightly. The depths of Pluto Cave are eternally dark, so take at least two ...
- Trailer Life Directory. 2004. p. 320. Retrieved February 10, 2018.
Pluto's Cave, named after the Roman god of the underworld, was formed by an eruption a basaltic lava which orginated from a vent about 8 miles to the northeast. The lava flow is about 190,000 years old ...
- Wells, H.L. (1881). History of Siskiyou County, California Illustrated with Views of Residences, Business Buildings and Natural Scenery: And Containing Portraits and Biographies of Its Leading Citizens and Pioneers. Siskiyou Historical Society. p. 36. Retrieved February 10, 2018.
The largest, however, is one discovered near Sheep Rock in the spring of 1863, by Nelson Cash, while hunting estrayed cattle. In April of the same year, George W. Tyler and Elijah Heard made an extended exploration of the cave and christened it Pluto's Cave. The entrance was about five hundred feet above the valley, being some three miles up the slope of the mountain. They entered through an opening ten feet high and twenty wide, and advanced through a succession of halls and chambers, or caverns, until they passed through an opening thirty feet square into the large cavern, or cave proper. They traversed this cautiously, over piles of fallen rocks and other obstructions, until they came to where an immense heap of rocks barred further progress. The distance to this point from the entrance they estimated at from one and one-half to two miles, and how far beyond the barrier of rocks it extended could not even be conjectured. Quite a current of air was felt in the cavern, nearly extinguishing their candles, caused by a subterranean river, another cavern, or a second entrance beyond. In the main cavern were found a pile of faggots and other evidences of fire, that bore the appearance of having been there for years, perhaps centuries, and probably had been, as the existence of the cave was unknown to the Indians. The walls within are very dry, the usual dampness of a subterranean cavern being absent, thus contributing to the preservation of objects deposited there. Quite a number of people have visited the cave at different times, but a more thorough exploration than this has never been made. Several smaller caves have been discovered within a radius of a few miles, but none of so great dimensions as this.
- Gudde, E.G.; Bright, W. (2010). California Place Names: The Origin and Etymology of Current Geographical Names. University of California Press. p. 296. ISBN 978-0-520-26619-3. Retrieved February 10, 2018.
- Hoover, M.B.; Rensch, H.E.; Rensch, E.G.H.; Teiser, R. (1948). Historic Spots in California. Stanford University Press. p. 170. Retrieved February 10, 2018.
Brewer visited Pluto's Cave on October 10, 1863, shortly after its discovery.
- Wilson, R. (2006). The Explorer King: Adventure, Science, and the Great Diamond Hoax--Clarence King in the Old West. Scribner. p. 93. ISBN 978-0-7432-8900-9. Retrieved February 10, 2018.
- Brewer, W.H.; Farquhar, F.P. (1930). Up and Down California in 1860–1864: The Journal of William H. Brewer. Yale University. Philip Hamilton McMillan Memorial Pub. Fund. Yale University Press. Retrieved February 10, 2018. Available online: "Up and Down California in 1860–1864; The Journal of William H. Brewer: Book 4, Chapter 7". Yosemite Online. Retrieved February 10, 2018.
- Selters, A.; Zanger, M. (2006). The Mt. Shasta Book: A Guide to Hiking, Climbing, Skiing, and Exploring the Mountain and Surrounding Area. Wilderness Press Series. Wilderness Press. p. 98. ISBN 978-0-89997-404-0. Retrieved February 10, 2018.
- King, C. (1872). Mountaineering in the Sierra Nevada. Nineteenth Century Collections Online: Science, Technology, and Medicine: 1780–1925, Part II. J.R. Osgood. p. 261-. Retrieved February 10, 2018. Available online: "Clarence King: Mountaineering in the Sierra Nevada: Chapter XII". Yosemite Online. Retrieved February 10, 2018.
- Douglas, Joseph C. (July 2003). "The Romantic and the Caves: John Muir and the Underground Environment" (PDF). Journal of Spelean History. 37 (124): 37–42. Retrieved February 10, 2018.
- Muir, J. (1888). Picturesque California and the Region West of the Rocky Mountains, from Alaska to Mexico. Picturesque California and the Region West of the Rocky Mountains, from Alaska to Mexico. J. Dewing Company. Retrieved February 10, 2018. Available online: Muir, John. "Shasta Rambles and Modoc Memories, Chapter 5 of 'Steep Trails' by John Muir (1918) - The Writings of John Muir - John Muir Exhibit (John Muir Education Project, Sierra Club California)". Sierra Club Home Page. Retrieved February 10, 2018.
- Reports of the University of California Archaeological Survey. Reports of the University of California Archaeological Survey. University of California Archaeological Survey, Department of Anthropology, University of California. p. 2. Retrieved February 10, 2018.
- "Pluto's Cave". Klamath National Forest. October 6, 2017. Retrieved February 10, 2018.
- Hinds, N.E.A. (1952). Evolution of the California Landscape. Bulletin (California. Division of Mines and Geology). California State Printing Office. p. 120. Retrieved February 10, 2018.
The largest of the lava tunnels is Pluto's Cave discovered in 1863 which once could be traced for a mile and a half or two miles. Now probably half a mile is as far as it can be followed, access being easy in places where the roof has collapsed. Most of the accessible part of the tunnel has a diameter of 30 to 50 feet but in places it reaches 80 feet. The floor is heavily covered by blocks which have fallen from the roof and by sand drifted in from dunes on the surface.