From a sign at the site:
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 (in other words, no climbing allowed). 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.
