Sunnyside Mine group

Bonita Peak, Gladstone, Eureka Mining District, San Juan County, Colorado, USA

Key Information

Do not enter mining areas without proper authorization.

The Sunnyside Mine group, located at Bonita Peak near Silverton, Colorado, is a historic mining site in the San Juan Mountains, known for its rich mineral deposits and past operations.
It produced gold, silver, lead, zinc, copper, and notably rhodochrosite, with the latter being highly prized by collectors.
The area features volcanic rock formations, with minerals formed through hydrothermal processes, and has a cold, snowy climate influencing mining activities.
Mining started in 1873, had multiple operational periods, and closed in the 1990s, now part of a Superfund site due to environmental issues.
Local culture centers on mining history, with Silverton offering historic sites and outdoor activities, while the ecology includes alpine forests and tundra.

Geographic Location

The Sunnyside Mine group is nestled in the rugged San Juan Mountains of southwestern Colorado, USA, near the town of Silverton and the ghost town of Animas Forks. Bonita Peak, with an elevation of 13,286 feet, is a prominent feature, offering stunning views and a sense of isolation that defines this high-altitude region.

Minerals Produced

This locality is renowned for producing a variety of minerals, including gold, silver, lead, zinc, copper, and manganese. Among these, rhodochrosite stands out, with its vibrant pink crystals being highly sought after by mineral enthusiasts for their aesthetic appeal and rarity in such quality.

Geological Structure

The geological setting is dominated by volcanic rocks, part of the San Juan volcanic field, where mineralization occurred through hydrothermal processes. These veins, formed within the volcanic collapse structures, are a testament to the area's dynamic geological history, offering a glimpse into the forces that shaped its mineral wealth.

Mining History

Mining at Sunnyside began in 1873, with significant operations in the early 20th century, producing up to 1,000 tons of ore daily. It experienced closures and reopenings, notably in the 1950s and 1980s, before ceasing operations in the 1990s. The site is now part of the Bonita Peak Mining District Superfund site, addressing environmental contamination from past activities.

Local Culture and Characteristics

The nearby town of Silverton, a National Historic Landmark, embodies the region's mining heritage with preserved historic sites and a vibrant community life. Visitors can explore old mining towns, enjoy local breweries, and participate in festivals that celebrate the area's history, blending tradition with modern outdoor pursuits.

Climate and Ecology

The climate is alpine, with cold, snowy winters and cool summers, receiving significant snowfall that shapes the seasonal accessibility of mining sites. The ecology features diverse high-altitude environments, from spruce and fir forests to alpine tundra, supporting unique wildlife and influencing the historical mining operations through environmental challenges.