Coulee Serenity

Forming an estimated 50 million years ago in the Bearpaw sea during the Cretaceous period, the spherical shale concretions (red rocks of Red Rock Coulee) were formed when fossils gathered mineral cement, primarily calcite and ironstone, then grew outward as circulating water brought more of the mineral cement to the bits of shell, bone and other biological debris. The mineral cement makes them resistant to erosion whereby the surrounding earth drops away leaving them exposed over time. Though we didn't find any ammonites in this ammonite rich field, we always keep our eyes peeled for rattlesnakes.