The Foothills Erratics Train is a long, narrow ( wide), linear scatter of thousands of typically angular boulders of distinctive quartzite and pebbly quartzite that that lie on the surface of a generally north-south strip of the Canadian Prairies. These boulders, which are between and in length, are glacial erratics that lie upon a surficial blanket of Late Wisconsin glacial till. The largest glacial erratic within the Foothills Erratics Train is Big Rock.