New Mexico Mineral Symposium — Abstracts

Located in 1875, a year before Ouray County was carved out of the San Juan territory, the original claims of the Grizzly Bear mine are located up Bear Creek, on the northwest slopes of Engineer Mountain, described by Ransome in USGS Bulletin 182 on the Silverton quadrangle.

The Grizzly Bear mine is a gold-silver mine, having produced almost $1,000,000 in ore values between 1875 and 1910. Always hampered by the lack of transportation, the mine nevertheless was long-considered a promising property. Nearly every prominent name in Ouray County mining has been associated with the Grizzly Bear mine at one time or another since its early days.

A tremendous amount of money was poured into the development of the Grizzly Bear mine between 1896 and 1900, improving the road up to the mine, building a boarding house, and extending several tunnels on the property hundreds of feet. Unfortunately, the mine went into receivership and was eventually sold to a man named Lars Pilker just after World War I. In the early 1920s, looking for financing to develop the mine, Pilker sold a partial interest to John Zanett. Zanett and his family had come to Ouray just after the end of World War I from the Italian Piedmont by way of New York and Ohio. Over the next half-century, Pilker and Zanett maintained a partnership and a love-hate relationship while trying to develop the Grizzly Bear mine. Both men died before their dream was ever realized. It fell to John Zanett's youngest son, Fred, who had made a considerable fortune in the oil business, to realize his father's dream.

Because transportation had always been the limiting factor in profitably mining the Grizzly Bear, and because building a road up Bear Creek was impossible, proper access to this mine had to be achieved by driving a haulage tunnel either from the south or from the north. In the 1970s, Fred Zanett and associate Caswell Silver thus began acquiring patented mining claims that lay north of the Bear Creek drainage, with the intention of driving a haulage tunnel from the Amphitheatre (the high cirque east of Ouray in which the Forest Service maintains a campground) south toward the old Grizzly Bear workings. An operating company, called Savage Mining Corporation, was formed by the four grandchildren of John Zanett, and work commenced driving the haulage tunnel in 1978, named in honor of their grandfather. After more than a dozen years of work and 8,500 feet of drifting, the John Zanett Tunnel now connects with the historic workings of the Grizzly Bear mine and has been further extended south into new territory along the Grizzly Bear vein system. The mine now includes more than 120 patented and unpatented mining claims.

Even in its early days, the Grizzly Bear mine was known for its rhodochrosite. In a 1910 mine report, mining engineer Chester Ingersoll described the Grizzly Bear vein as "a 'true fissure' with well-defined walls from 15 to 30 inches wide and traceable on the surface for several miles. . The vein filling consists in the main of quartz and rhodonite, a manganese silicate locally termed 'pink quartz,' besides these, quartz crystals and very beautiful crystals of rhodochrosite (a manganese carbonate)." It was certainly unusual for a mining engineer to even bother mentioning gangue minerals, so one may infer that the Grizzly Bear rhodochrosites were most unusual.

While the Zanett Tunnel was being constructed, several zones were encountered that contain rhodochrosite specimens. One zone contained vugs of fern-green quartz crystal plates colored by the inclusion of chlorite. Baby-pink rhodochrosite rhombohedra up to 0.5 inch across were sprinkled on top of the quartz. Farther along the haulage, a large watercourse contained plates up to 12 inches
across of white drusy quartz with etched rhodochrosite crystals up to 2 inches on edge perched on the quartz. The rhodochrosite color here ranges from light pink to strawberry pink, but heavy iron staining on the specimens makes determination of the true color often difficult. A few rhombohedra were completely coated by a quartz druse, thus indicating several generations of crystal formation.

The largest rhodochrosite crystal found at the Grizzly Bear mine in modern times is a rhombohedron completed coated by a fine-grained druse of white quartz. Nearly 4 inches on edge, this specimen was collected by Peter Klein, operating partner in the mine, and given to the author as a gift. It came from a large crystal cavity in the Zanett haulage near the site of the refuge station, 6,000 feet from the portal. One corner of the quartz encrustation was removed prior to its presenta-tion to show the underlying rhodochrosite. Although the specimen has been altered by the removal of one small section of the quartz coating, it remains one of the largest and best rhodochrosite crystals to have come out of this or any Ouray County mine.

The mine also contains several zones with pale-green fluorite cuboctahedra to 1 inch on edge, often clusters to 3 inches across, implanted on plates of large milky quartz crystals. In another area of the main haulage, about 6,500 feet in from the portal, the mine owners invited the author to collect some interesting lavender fluorite cubes, somewhat etched, that were up to 1.25 inches on edge. Another zone contains pale-green fluorite cubes with red sphalerite with small rhodochrosite crystals.

Other mineral species found at the Grizzly Bear since 1980 include red, amber, and black sphalerite; small white barite rosettes; brown and cream calcite scalenohedra; small, twinned chalcopyrite; chlorite; galena cubes; tiny hexagonal hematite crystals; gemmy huebnerite; cubic pyrite; massive rhodonite; cinnamon-brown siderite; small tetrahedrite crystals; and silver wires.