Named in 1928 after the song "Big Rock Candy Mountain," by Harry McClintock," became popular. Highway 89 near Marysvale, Utah.
Approximately 22 to 35 million years ago, a cluster of stratovolcanoes (volcanoes similar to Mount St. Helens) erupted, depositing large volumes of lava and ash. Known as the Bullion Canyon Volcanics, these volcanic rocks are more than 3,000 feet thick.
Approximately 21 million years ago, at least six magma bodies intruded the overlying Bullion Canyon Volcanics. Through a complex chemical process involving hydrogen sulfide, steam, ground water, and oxygen, the original volcanic rock was partially altered or totally replaced. The vivid colors that one sees at Big Rock Candy Mountain are the direct result of this mineralization.
The yellow, orange, and red colors are from the presence of iron minerals, such as jarosite, hematite, and pyrite. The white color is due to the presence of alunite and kaolinite, minerals rich in potassium.