About 180-140 million years ago during the Jurassic, shifting dunes of fine-grained sand covered what is now Utah and parts of Colorado and Arizona. Over time, as sediment filled over dunes, they hardened into salmon-colored rock known as Entrada Sandstone.
Fast forward to the modern day. Rain, wind and freezing has eroded away much of the rock covering the Jurassic-era sandstone and shaped it into interesting geological features. One common sight in the national park is an arch, such as The Windows:
More than 2,000 cataloged arches have been found in the park’s nearly 120 square miles. The Windows are among the easiest to reach by day hiking the 1-mile round-trip Windows Trail.
Also see:
• Children will love day hike on Windows Trails in Arches National Park
• Best trails for seeing Arches National Park’s numerous wonders
Learn about other great national park day hiking trails in my Best Sights to See at America’s National Parks guidebook.
