During that time, sediment from beaches and shorelines deposited silt and sediment that built up as seas retreated and advanced, and eventually the silt was compressed into the rock we've got today. Later on, a layer of salt beneath the rock began to push upward, creating pressure and causing the sandstone to crack and fault into fissures. And as the sandstone rose, it was exposed to more precipitation, which speeded along the erosion process. As more sandstone became exposed, more weathering took place, and eventually the arches were formed. In much the same way, arches eventually collapse upon themselves, but as more rock is exposed more arches form.
Geology is alive and kicking in southern Utah.
Of course, all this talk of 'millions of years' is a little hard to grasp. I mean, it's hard to think in terms of decades, much less centuries. A million is incomprehensible, especially when it means a rock is being chipped apart, grain by grain. Woodpeckers made them. You know, I've been talking about all these holes in the rocks but still have not talked about the hole in the rock, better known as Hole N' The Rock.