Like the surrounding mountains, the pass was created by glaciation and erosion over thousands of years. Before European-American settlers arrived, it was in the territory of the Ute Native American tribe. One of the earliest sightings by a European-American was in 1806, when Zebulon Pike, mapping the southern boundary of the Louisiana Purchase, spotted the gap in what would later be named the Sawatch Range from the upper Arkansas River valley. It was not explored until Ferdinand Hayden and his team surveyed it in 1873. At the time it was known as Hunter Pass.