Utah is a state best known for its towering red rock arches, desert plateaus, and snowy peaks. But there's another Utah most people never see, the one hidden below the surface. Beneath the cliffs and canyons lies a vast and wild underground world: deep caves, flowing rivers you'll never spot from the road, and geological systems that have taken millions of years to carve into place. What makes Utah's subterranean scene so unique is the sheer variety of how it formed. Volcanic flows, limestone erosion, tectonic shifts... they've all played a part. In fact, some rivers here begin underground and…