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History of Cascade Canyon Lapis and Corundum Deposits, San Gabriel Mountains, CA

Last Updated: 15th Oct 2012

By Robert Housley

Over the past one hundred years the Cascade Canyon lapis-lazuli and corundum deposits in the San Gabriel Mountains, San Bernardino County, California USA have become well known and almost legendary, yet it seems safe to say that few living people have ever been to the outcrops. These occur in terrain that is steep, rough, brushy, and trail less, and where mining is currently not allowed. Because of the general interest, though, it seems worthwhile to document what I have been able to learn about the discovery and mining history of these interesting deposits.

The first known published mention of a mineral from Cascade Canyon is of lapis-lazuli and it occurs in the book “The Natural History of Gems or Decorative Stones” by C. W. King, published in London (KING, 1867). It is a footnote on page 273 which states “Although plentifully found in China, and of late years in California [he is speaking of lapis-lazuli], the product of both of these countries is too full of pyrites and white veins to be available for the Glyptic art and is only suitable for calcination”. Cascade Canyon is the only known location for lapis in California and this seems to imply that some quantity of it had already been traded on the world market by 1867.

However, it appears to have remained largely unknown locally for quite some time longer. No mention of it was made in Henry G. Hanks list of California minerals (HANKS, 1884), nor in G. F. Kunz “Gems and Precious Stones of North America” (KUNZ, 1890).

Apparently, however, the occurrence of gem-quality blue lapis-lazuli in Cascade Canyon was reported to D. B. Sterrett of the United States Geological Survey by mineralogist R. M. Wilke of Palo Alto in 1910 and was first published in the USA in 1911 (STERRETT, 1911) under the mineral name lazurite. It was also mentioned by Austin F. Rogers in 1912 who, “because of its association with pyrite”, also identified it as lazurite (ROGERS, 1912). Slightly earlier in 1910 word of the occurrence of ruby corundum in Cascade Canyon was first published in an abstract (LOUDERBACK and BLASDALE, 1910).

Actually almost all of what we know about the early history of lapis-lazuli mining in Cascade Canyon comes from an article by Gordon Surr published in December of 1913 (SURR, 1913). I am going to quote a lot of that article. However, I think it will help to put it into context to say a little about the broader history of mining in this part of the San Gabriels. That I get largely from the booklet “Mines of the San Gabriels” by John W. Robinson (ROBINSON, 1986).

Placer gold was discovered at Baldy Notch near the head of San Antonio Creek in 1871, and mining there got underway in earnest about 1878. During the 1880s six to eight mining companies were operating in the region and getting out nice nuggets. The main problem was a shortage of water during most of the year. In 1893 the Hocumac Mining Company bought up all of the placer claims and built a long and expensive flume system to bring in adequate water for year round operation. In 1894 they operated apparently very successfully. However, their large scale operation caused severe downstream water pollution, and the people downstream were using the creek water for residential and irrigation purposes. Thus in July of 1895 the San Antonio Water Company got a court injunction prohibiting the mining company from causing downstream pollution. That effectively put an end to hydraulic mining in the canyon, and the water company took over the placer mines in 1900 and destroyed the flume. A little hard rock gold mining continued up to and possibly slightly past the turn of the century.

In an additional interesting bit of background The Eleventh California State Mining Bureau Report published in 1893 (IRELAN, 1893) describes something it calls “The Lordsburg Stampede”. It states that in March of 1892 word went around of a rich silver and gold strike in the hills north of Lordsburg. The Lordsburg of that day corresponds in location to the City of La Verne of today. Thus north of Lordsburg would likely mean up San Antonio Canyon. It says that farmers left their fields and shop keepers left their stores, but that the stampede was over, and all but a few diehards were back within 3 weeks.

I think it is safe to assume that during the years of active mining and the Lordsburg stampede many prospectors scoured San Antonio Canyon and all of its tributaries, and probably some of them recognized lapis and knew that it had some value. Thus Surr’s contention in the quote below that all the lapis that was easy to find had been picked up by 1913 seems quite plausible.

Excerpt from Gordon Surr. “Lapis-lazuli, the sapphire of the Bible, has hitherto, as far as I know, been found in but one locality in the whole of North America and, unfortunately, the stone seems to have been worked out at this spot. What is virtually an obituary notice may nevertheless be of interest and no apology is therefore offered for going into some detail.

Years ago blue rock was discovered in place on the steep north slope of the south fork of Cascade Canon, about 6000 ft. above sea 1evel, and about 1.5 miles in an airline easterly, and a little south from the "Hogback", a well known landmark in San Antonio Canon, of which Cascade Canon is a branch. The mouth of San Antonio Canon is 5 miles northerly from Upland, a small town 20 miles west of San Bernardino, Cal. on the main line of the Santa Fe railway, and electric cars now run hourly between Upland and the mouth of the Canon. The locality is about 7 miles from the end of this electric line, there being a good road for some 4 miles then 2.5 miles of trail, and finally a hard climb of half a mile up the steep, rocky bed of the canon. This blue rock was thought, at the time, to carry silver, and many prospectors still firmly cling to the erroneous ideas that the rare bromide of silver is not only blue, but also a fairly common silver mineral. The impression that silver was present was further strengthened by an individual, styling himself an assayer, who claimed to have tested the blue material with good results. Consequently, work was started on the blue outcrop, and a tunnel was also driven for some distance. The blue rock did not apparently go down more than a few feet, for the hole is said to have been abandoned when 15 ft. deep, being now almost full of earth and rocks, which slide down the hill-side with little provocation.

Later, the blue material was identified as lapis-lazuli by John T. Reed, then an assayer and chemist of San Bernardino, and he and his son, after working on the claim, decided that the prospects were not encouraging. Unfortunately nothing seems to have been published on the subject at the time.

Several years ago, San Antonio canon was visited by Professor Lauterbach of the University of California, in company with R. L. Wilke, the well-known mineralogist of Palo Alto, Cal., and they picked up pieces of blue rock in the main canon, and also found a boulder of gray limestone weighing about a ton and sprinkled all over with spots of lapis-lazuli. In the summer of l913 Mr. Wilke was again in the region this time with Professor Arthur S. Eakle, also of the University of California, but no lapis-lazuli was then found.

The first I heard of the presence of the mineral there was in August, 1913 when William Foshag of San Bernardino, told me that he once came across a small boulder containing lapis-lazuli near the mouth of San Antonio canon. Mr. Foshag, at that time had just begun to study minerals and did not long keep the piece he knocked off the boulder, thinking the blue substance was probably copper carbonate and later learning its true nature.

L. J. Childs, of Rialto, Cal., having heard a short time before of Mr. Foshag's discovery, visited the canon in September, 1913, and found what was probably, the same small boulder, as hammer marks were plainly to be seen. Mr. Childs, Dr. W. F. Prince, of San Bernardino and the writer then commenced a systematic search for the mineral in place, making at intervals, several trips, each meaning a long and strenuous day. We picked up "float", or loose pieces of rock, containing lapis-lazuli, the pieces being small, few, and far between, and at length, what with the float and information otherwise gained, were much encouraged by seeing the body of an old wheelbarrow jammed in among rocks in the bed of Cascade canon, below the forks. This indicated that we were nearing our goal, and never before did I realize what a welcome sight such a humble implement could be. We had already visited the North fork without seeing float, so we ascended the South branch, and finally found the old working some three-quarters of a mile beyond the whee1-barrow. We, however, could see no lapis-lazuli in place, but got pieces from the stream bed in the immediate vicinity, and from the hill-side directly below the workings, these pieces having evidently been blasted out by our predecessors.

The material is not of good quality, being apparent1y an impure, dark-gray quartzite streaked with parallel, pale to deep-blue bands, from an eighth to over half an inch wide; the blue and other parts of the rock showing abundant fine grains of pyrite. The results of an assay were a trace of gold and no silver. The rocks of the region are of sedimentary origin, being mainly quartzites and limestones, the contacts and pronounced cleavage or bedding planes of the quartzites having an easterly course and dipping steeply toward the north at the old workings. Here the lower quartzite is light gray, showing pyrite and iron oxide stains; then comes dark quartzite containing pyrite: then a few inches of soft shaly material, and then an overlying bed of limestone. The lapis-lazuli doubtless occurred in the outcrop of the dark quartzite, and no reason could be readily seen for its presence here, and not elsewhere along this or other contacts of quartzite and limestone in the region. Granite boulders were noted in the bed of the canon, but no igneous rocks were seen in place in the vicinity, making the occurrence appear unusual. The float we found is of the same general character as the material obtained near the old workings, and one small boulder was some 6 miles from these workings. Time is certainly not "of the essence" in the journeys of boulders down stream beds, for in this region they are at rest most of the year and only move, if at all, during occasional periods of high water. Yet, in spite of years of exposure, the pieces of float, when broken, show unaltered, fresh grains of pyrite, owing to the hardness and close grain of the rock, and possibly to the presence of organic matter in the dark quartzite, which would tend to prevent oxidation of the pyrite.

Weathering, moreover, seems to have little or no effect upon the blue color. We saw nothing of the large boulder found by Mr. Wilke but, what with float and the material close to the old workings, noted, in all, at least 150 lbs. of rock containing more or less lapis-lazuli, and there is a possibility that a thorough search might reveal other occurrences along the same, or similar contacts.

From this account by Surr four interesting things stand out. One, we learn that at some time during the mining and prospecting era the lapis was thought to be silver ore and some exploration work was done on the outcrops, and maybe some trails were made. This time probably corresponds with the Lordsburg stampede, so would have been 20 years before Surr’s visit. Two, we learn that at some time well prior to 1913 Reed and son had made an attempt to mine lapis from the source, but had given it up as unprofitable. Three, we learn that the old abandoned workings found by Surr were on the north wall of the south fork of the canyon. Four, we learn that all the easily collectible lapis from San Antonio Canyon, Cascade Canyon, and the old mine workings was gone by the end of 1913.

It is also interesting to note that 3 of the people mentioned in Surr’s account had minerals named after them. They are wilkeite, foshagite, and eakleite. Unfortunately the first was later found to be identical to fluorellestadite and the last was subsequently found to be identical with xonotlite.

The XVth Report of the California State Mineralogist published in 1917 (HAMILTON, 1917) mentions corundum from Cascade Canyon as a possible abrasive resource if it could be concentrated efficiently.

Continuing on, in the 1922 edition of “Minerals of California”, Eakle (EAKLE, 1923) lists the north wall of the south fork of Cascade Canyon occurrence under lazurite, but states that “the minerals optical properties better match sodalite”.

The next mention I have found of the location is in a “Rocks and Minerals” magazine account by Fred W Schmeltz (SCHMELTZ, 1932). In it he states that there is a good trail from the end of the road to the mine although the last part is pretty steep. He describes an inclined shaft about 10 feet deep with a ladder and a windless and shows a picture of the shaft in which the windless can be seen. It appears obvious that someone has built a trail, cleaned out the old hole, and done some more work since Surr visited the area.

It needs to be mentioned here that in May 1928 the US Congress passed Public Law 578 “The Watershed Withdrawal and Restoration Act” that led to restrictions on the ability of anyone to prospect and mine in this Cascade Canyon area. In 1929 a short time after passage of this act the Angeles National Forest withdrew almost all their land on the south side of the San Gabriels from mining and prospecting. The withdrawal is still in effect and includes all of the San Antonio Canyon drainage.

The next article mentioning Cascade Canyon appears in 1936 and is by Merriam and Laudermilk (MERRIAM and LAUDERMILK, 1936). It describes a nearly pure diopside that they found in association with sodic tremolite as float near the mouth of the canyon, and also mentions corundum, fushite, and lapis-lazuli having been found there. It suggests that the lapis might be sodalite or hauyne. It also mentions that minerals resembling glaucophane and hydrotroilite occur there. In a large scale sketch map appearing in the article the authors have seriously mislocated Ontario Peak so that it appears to be southeast of Cascade Canyon, thus putting Cascade Canyon on its northwest side. This mistake has been repeated several times in subsequent articles. In reality all the interesting minerals from Ontario Peak occur around Cascade Canyon on its southwest side.

In 1937 Hubert Popenoe, then a student at Pomona College, wrote a student paper on the Cascade Canyon lapis-lazuli, which was only published much later (POPENOE et al., 1982). In it he correctly located Cascade Canyon on the southwest side of Ontario Peak, and in agreement with Surr located the mine on the north bank of the south fork of the canyon. He states that the old hole had been cleaned out and active mining on a small scale had taken place since the account by Surr. He gives a brief account of the metamorphic bedding of the host rock and adds graphite to the list of minerals found there.

In thin section, associated with the lapis he saw calcite, diopside, forsterite, phlogopite, pyrite, pyrrhotite, small amounts of a zeolite, and a black iron sulfide “having many of the properties of melnikovite”. He determined the lapis to have an index of refraction of 1.493. Through micro chemical tests he concluded it to be a solid solution of nearly equal amounts of lazurite and hauyne.

In 1938 Austin F. Rogers (ROGERS, 1938), who was one of the first people to mention the Cascade Canyon lapis in the US literature, although apparently he never personally visited the site, wrote an article describing what he by then knew about the occurrence and about the outcome of chemical tests he had recently conducted. He remembered that as some time in the past a company named “The Lapis-Lazuli Mining Company” had been formed to mine the deposit, but had not been very successful.

Based on examination of a polished sample and thin sections he noted that pyrite grains occur both disseminated throughout the specimens and in bands parallel to the lapis. He found the most common minerals associated with the lapis to be diopside, then muscovite, with calcite only sometimes being present. He found the index of refraction of his lapis to be 1.503. On the basis of his micro chemical tests he concluded that his lapis should be referred to as sulfide bearing hauyne. It is worth noting however in the same article he suggested demoting lazurite to a group name.

In 1935 Laudermilk and Woodford published an abstract (LAUDERMILK and WOODFORD, 1935), and in 1940 a paper (LAUDERMILK, 1940) describing a hydrous iron sulfide, which they called hydrotroilite, from Cascade Canyon, and in it still mistakenly said the canyon was on the northwest side of Ontario Peak. From their thin section study they describe the hydrotroilite as occurring along cracks in serpentinized forsterite in a calcite-forsterite rock. They are not describing forsterite of mineralogical interest.

In the 36th report of the California State Mineralogist (BRADLEY, 1940) also published in 1940 Bradley mentions that two specimens were analyzed by the State laboratory during the year. One was simply stated to be forsterite from the northwest side of Ontario Peak. The other was stated to come from Cascade Canyon and to also contain hydrotroilite. Although there is no longer any record of who submitted these samples it seems highly likely that they came from Laudermilk and Woodford and that neither of them was actually from the northwest side of Ontario Peak.

In their paper Laudermilk and Woodford also mention that garnet, diopside, corundum, tremolite, forsterite, sodic amphibole, lazurite, fushite, and other minerals all occur within a distance of three quarters of a mile, and then carelessly state that most of them occur in crystalline limestone. This may be the source of the mistaken belief, perpetuated in many listing since of minerals from California, that the Cascade Canyon corundum is found in limestone. In fact it never is.

The August 1946 issue of Desert Magazine (EATON, 1946) has a brief report on a field trip by the Pomona Valley Mineral Club to Cascade Canyon and mentions that about 20 minerals including lapis can be found there.

The first comprehensive study of the geology of the Cascade Canyon area is contained in a UCLA Ph. D. thesis submitted in 1958 by Perry Ehhlig (EHLIG, 1958), which covers the geology of the whole greater Mount Baldy area. In it he divides the Cascade Canyon metamorphics into 15 units, numbered from bottom to top. He states that the larger corundum crystals originate in a layer of rock only a few feet thick near the base of unit 6. He further states that the lapis which occurs more erratically in units 7 and 8 is, in his opinion, a result of secondary alteration and metasomatism of the originally regionally metamorphosed material. Ehlig makes no mention of the mining history of the region, however, in a map that he gave to John Schwarze he shows lapis at the locations of both the old mine mentioned several times above, and the new mine to be mentioned below.

The start of the more recent era of lapis mining in Cascade Canyon is described in a Lapidary Journal article of April 1961 (BORCHERT, 1961). Apparently Professor Laudermilk had taken a Pomona College geology field trip group to the old mine site in the south fork in 1948. Following that field trip, one of the students, John Earnsberger had made many trips to the area over a period of quite few years attempting to find a commercial quantity of the lapis. Meanwhile William Peck and his son Phil, along with some of his son’s friends, had been trying to find the source of the lapis by panning the stream and working their way up. After making 15-20 trips a year over a period of about 4 years they eventually found a fist sized piece of lapis near the base of a small waterfall. Exploring that area they discovered the north fork of the creek. The following week they came back and followed up the north fork eventually discovering a large lapis vein.

Shortly afterward Earnsberger and Peck were introduced by a mutual friend and formed the Cascade Canyon Gem Company. The company obtained a lease on 120 acres surrounding the property and mined on a modest scale for several years. They were not allowed to build a road, were only allowed to use hand tools in the mining, and they had to carry the material down on their backs. Eventually they recovered all that was profitable to take out under those conditions and turned the lease back to the Forest Service. In a private communication Phil Peck told me that landslides had completely erased any evidence of the old working in the south fork of the canyon by the early 1960s.

Almost 20 years after Cascade Canyon Gem Company pulled out Sam Speerstra filed a mining claim on the same area and called it the Big Horn Mine. He brought in a portable drill and explosives and blasted the vein. He wrote and article for Lapidary Journal (SPEERSTRA, 1979) describing the opening of the Big Horn Mine and advertised some material for sale from it. In the article Sam carefully does not mention Cascade Canyon, but Phil Peck has told me he can tell from the pictures that it is the same site that they mined. Because of the withdrawal mentioned above the Speerstra claim was never valid. The Forest Service soon put a stop to his efforts. In 1984 an appeals court ruled his claim to be null and void from the beginning. Only amateur collecting has occurred there since then and because of the rugged terrain the outcrop areas are seldom visited. Any old trails that once existed have been totally obliterated by landslides and vegetation.

On the other hand the landslides and storms continually bring material down to where it can be found along lower Cascade Creek in the vicinity of Barrett-Stoddard Road, or just below its mouth along San Antonio Creek. Corundum and other interesting metamorphic minerals are abundant in these places. Lapis is now extremely rare.

The blue mineral itself always occurs as small grains intergrown with other minerals. No modern studies have definitely confirmed its identity, and certainly nobody has explored whether it in fact has a range of compositions. The prevailing opinion seems to be that it is lazurite, and the association with pyrrhotite mentioned by Popenoe certainly favors that view, for at least for any samples with this association.

In compiling this information I have had help from several people. Most interestingly Phil Peck discussed with me some of the adventures and frustrations he and his family and friends had mining lapis in the canyon. Cathy Casey let me copy a map and notes on mineral locations in the region given to her by Hap Pierce. Similarly, John Schwarze gave me a map on mineral locations in the region prepared for him by Perry Ehlig. Rose Tozer of the GIA library found the information on the legal history of the Speerstra Claim for me. Niki Forgues found the 1961 Lapidary Journal article for me. This draft summarizes what I know now, or think I know now. I will welcome any corrections or additions.


Borchert, N., 1961. A new strike of Lapis-Lazuli in California. Lapidary Journal XV, 106-107.
Bradley, W. W., 1940. Thirty-sixth report of the State Mineralogist: California Division Mines Report 36, 456
Eakle, A. S., 1923. Minerals of California. California State Min. Bur., Bull. 91, 328-328.
Eaton, A. L., 1946. Gems and Minerals: Pomona Club Collects at Mineralized Cascade Canyon. The Desert Magazine, 31.
Ehlig, P. L., 1958. The Geology of the Mount Baldy Region of the San Gabriel Mountains, California, UCLA.
Hamilton, F., 1917. Report XV of the State Mineralogist, mines and mineral resources of portions of California. California State Office, Sacramento, CA, Sacramento, CA, United States (USA), 20
Hanks, H. G., 1884. Fourth annual report of the State Mineralogist, for the year ending May 15, 1884. Annual Report of the State Mineralogist 4, 1-410.
Irelan, W., Jr., 1893. Eleventh report (First biennial) of the State Mineralogist, two years ending September 15, 1892. California State Office, Sacramento, CA, Sacramento, CA, United States (USA), 246
King, C. W., 1867. The Natural History of Gems or Decorative Stones, London.
Kunz, G. F., 1890. Gems and Precious Stones of North America, New York.
Laudermilk, J. D., 1940. Hydrous iron sulphide in California crystalline limestone. American Mineralogist 25, 418-424.
Laudermilk, J. D. and Woodford, A. O., 1935. Black iron sulphide in a California crystalline limestone [abstracts]. Pan-American Geologist 63, 320-320.
Louderback, G. D. and Blasdale, W. C., 1910. Ruby corundum from San Bernardino County, California. Science, 793.
Merriam, R. H. and Laudermilk, J. D., 1936. Two diopsides from southern California. American Mineralogist 21, 715-718.
Popenoe, H., Fife, D. L., and Minch, J. A., 1982. Lapis-lazuli from Cascade Canyon, Mt. Baldy Quadrangle, California. South Coast Geol. Soc., United States (USA), 522-523
Robinson, J. W., 1986. Mines of the San Gabriels. La Siesta Press, Glendale.
Rogers, A. F., 1912. Notes on rare minerals from California. Columbia University School of Mines Quarterly, 373-381.
Rogers, A. F., 1938. Lapis lazuli from San Bernardino County, California. American Mineralogist 23, 111-114.
Schmeltz, F. W., 1932. Interesting Localities and How to Reach Them: Lapis-Lazuli in California. Rocks and Minerals 7, 69.
Speerstra, S., 1979. The Bighorn Mine; lapis lazuli from the High Sierras. Jewelry arts & lapidary journal 33, 1208.
Sterrett, D. B., 1911. Mineral Resources of the United States, 1910, part 2
Gems and Precious Stones. United States Geological Survey, Reston VA, 674-675
Surr, G., 1913. Lapis lazuli in southern California. Mining World, 1153-1154.

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