Geologists explore the hidden history of Colorado’s Spanish Peaks

If you’ve driven the mostly flat stretch of I-25 in Colorado from Pueblo to Trinidad, you’ve seen them: the Spanish Peaks, twin mountains that soar into the sky out of nowhere, reaching altitudes of 13,628 and 12,701 feet above sea level. In a new study, geologists from CU Boulder have laid out a timeline for the emergence of these majestic but isolated mountains. The team’s findings could bring scientists closer to answering one of the most enduring puzzles in Colorado geology: What made Denver, the Mile High City, a mile high?