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Explore California Gulch through Bill Harrington's 1992 painting, "The Roots of ASARCO." This acrylic on canvas painting was donated to the museum in 1995 and features California Gulch as it appeared in 1910. Learn about the history, geology, and modern uses of this interesting feature in Colorado's mountainous terrain. This interactive made possible through the support of Fred Mark and Vince Matthews. Copyright NMHFM 2020.


California Gulch as it looks today. Note the remaining cribbing used in terracing for foundations where buildings once stood, as well as ore bins where ore would be loaded into railroad cars. The asphalt road is Toledo Street (County Road 2) which follows the historic Rio Grande Railway grading.

Photo taken by Alfred Brisbois in the very early 1880s before mass industrialization of the gulch. Brisbois was a Leadville-based photographer during the 1880s but left for Chicago where he eventually found success during the 1890s.

The A.Y. and Minnie Mines in California Gulch in 1885. These mines were incredibly prolific producers of silver during that decade. Records indicate that ore extracted from these mines during this period was as much as 300 ounces of silver per ton of ore. That is an extremely high rate for a silver mine!

This was the initial source of the Guggenheim fortune. Meyer Guggenheim, an immigrant from Switzerland, invested in both of the mines in 1881. Mines throughout this area dealt with severe flooding of their tunnels and other underground workings. Guggenheim addressed this issue by hiring engineers specifically to deal with this problem. This investment paid off and the mines were able to efficiently access ores at a considerably more economic rate. During the 1880s, the A.Y. and Minnie mines made Guggenheim about $750,000 a year or a little less than $20,000,000 in today's rates.

California Gulch circa 1910.

These images show this portion of California Gulch today. Leadville's Mineral Belt Trail recreational trailway includes the area discussed in this interactive. The trail enters the gulch on the south side of the valley before making a turn at the point featured here before leaving the gulch heading north. The Mineral Belt Trail was opened in 2000 and was constructed on historic mine-train railway grades around the perimeter of Leadville. The trail is a paved, no-fee, eleven-mile loop for non-motorized travel such as walking, hiking, running, bicycling, snow-shoeing, and is groomed in the winter for cross-country skiing. This project was done as part of larger cleanup efforts which occurred between 1983 and 2011 by the EPA after the Leadville Mining District's designation as a Superfund site. Today, the Mineral Belt Trail is both an important attraction in Leadville's recreational tourism economy, and a living history museum with 37 signs detailing historic sites and structures around the Leadville Mining District.

Benjamin Guggenheim (1865-1912) was a son of Meyer Guggenheim who owned the AY and Minnie Mine described in this interactive. He lived in a house in Leadville on west 6th Street for a number of years (in a house that is still standing) supervising his family's interest in smelting in the Leadville area.

After his time in Colorado, Benjamin lived between New York and Paris and was, famously, onboard the Titanic at the time of its sinking. He was traveling with his butler, his mistress, and her maid from Paris to New York. After the Titanic struck the Iceberg, Benjamin and his butler helped the women in their party aboard lifeboats before returning to their quarters to change into their best suits to "go down like gentlemen." Their bodies were never recovered.

Meyer Guggenheim was born in Lengnau, Switzerland in 1828. He emigrated to the United States in 1847 and initially entered the importing business, primarily importing silks and other materials related to the tailor's trade. He invested wisely and successfully allowing him to expand his interests. During a trip west, he invested in the AY and Minnie Mines in California Gulch, which left him a multi-millionaire. He and his sons built one of the most financially successful businesses in the world including ventures in mining and smelting. Meyer passed away in Palm Beach, Florida in 1905 and was inducted in the National Mining Hall of Fame in 1989. -His son, Daniel Guggenheim (1856-1930) became the head of the family upon his father's passing and continued to build their companies and investments. Daniel was inducted into the National Mining Hall of Fame in 1988.

The geology of California Gulch and the surrounding region has motivated the majority of human activity and development in the area. About 40 million years ago, hydro-thermal activity in the area forced extremely hot water under high pressure through fractures in the existing rock. This hot water carried gold, silver, lead, zinc and other elements. As this water cooled, it deposited rich, mixed-metal veins throughout large ore bodies.

Picture: A specimen of chlorargyrite from the Leadville area containing about 70% silver.

California Gulch as it looks today. Note the remaining cribbing used in terracing for foundations where buildings once stood, as well as ore bins. The asphalt road is Toledo Street (County Road 2) which follows the historic Rio Grande Railroad grading.

California Gulch as it looks today. Note the remaining cribbing used in terracing for foundations where buildings once stood, as well as ore bins. The remaining headframe stands over what was the pump shaft for the A.Y. Mine. This shaft was not used for the transportation of ore, but was instead used to pump the mines clear of water. The asphalt road is Toledo Street (County Road 2) which follows the historic Rio Grande Railroad grading.

Why did California Gulch contain so much more placer gold than other similar gulches in the Leadville Mining District? The answer begins in the last ice age. Over thousands of years, rivers and streams erode the rock they are passing over and carry the eroded material downstream. Gold is much heavier than other river sediments and is deposited in pockets that accumulate over time. These are known as "placer gold deposits" or, simply, "placer gold."

Streams running through Evans Gulch and Iowa Gulch deposited placer gold in a fashion similar to California Gulch, however, due to the high altitude of the headwaters flowing into these two gulches glaciers would form in them permanently changing their geological histories. As these glaciers flowed through Evans Gulch and Iowa Gulch the massive power of the glaciers broke apart the existing deposits, churned all of the broken rock up together and deposited the material at the end of the glacial valley.

California Gulch avoided a similar fate as its valley beginning is much lower than the other two gulches. This allowed the placer gold deposits to remain along the river and streambeds flowing through that particular gulch.

During the middle of the 19th century, the headwaters of the Arkansas were largely unexplored. Prospectors involved in the Pikes Peak Gold Rush during the end of the 1850s knew there were reports of gold in what is now Lake County, but it was not until April of 1860 that gold was discovered in California Gulch. A prospector named Abe Lee was first to strike it big, and by the end of 1861 over 10,000 miners had produced 3.2 million dollars which is about 1.25 billion in modern terms.

This rush occurred before Leadville was developed or founded and the miners and prospectors of this period lived in a town called Oro City at the end of the gulch. Horace and Augusta Tabor (about 15 years before they made their fortune in silver mining) first entered the area with this gold rush. Augusta is the first recorded woman of European descent to enter California Gulch. Her husband and she mined and operated a supply store and boarding house. Augusta also worked as freightmaster and served as a postmistress for Oro City.