The bulk of the rocks at Alta, the rocks that we ski on, record the advances and retreats of ancient oceans that occupied this area of North America between 540 and 330 million years ago (Paleozoic Era). The oldest of these rocks is the Tintic quartzite a hard, dense, buff-colored rock that generally forms rounded and rolling terrain. The Tintic Quartzite underlies Mount Baldy and Sugarloaf Peak. It is also broadly exposed beneath the Sugarloaf chair lift, Ballroom and in much of Collins Gulch. The erosional characteristics of the Tintic Quartzite are responsible for much of the intermediate terrain at Alta.

The Tintic quartzite is well exposed below and around the Sugarloaf chair.