Hoodoos take millions of years to form and stand 5 to 7 metres tall. Each hoodoo is a sandstone pillar resting on a thick base of shale that is capped by a large stone. Hoodoos are very fragile and can erode completely if their capstone is dislodged. The protected Hoodoos site is a guaranteed spot to see Hoodoos but smaller versions of these sandstone giants can be found all over the Badlands. The Hoodoos make a great stop on the way to the Atlas Coal Mine National Historic Site in East Coulee. There's no cost to stop and visit.