 During the 1940s and 1950s, Wettlaufer played a key role in the excavations of the Head-Smashed-In Buffalo Jump site in Alberta and the Mortlach and Long Creek sites in Saskatchewan.Wettlaufer's work at Head-Smashed-In Buffalo Jump would lead eventually to its designation as a UNESCO World Heritage Site in 1981.He was one of the first archaeologists in Canada to use the radiocarbon dating method to establish the ages of various layers of settlements.