Dirt Dogs Excavation is about 5 days in on excavation work on a good-sized Round Pen arena in Elizabeth, Colorado which is perfect for exercising horses. This round pen features a crusher fine drain system on an exercise or “round pen” in Elizabeth Colorado. A sand footing surface will be soon be added on top of the crusher fines. If you look closely you will notice there is a slight dome built into the surface for drainage to help keep the arena dry and mud free. We’ll give you an update once we add in the sand footing.