Abstract Pennsylvanian–Early Permian carbonate sedimentation in east-central British Columbia records a complex history of changing environments influenced by evolving palaeogeography and climate. Newly recognized tectonically controlled features affected the distribution and variability of carbonate associations, providing new interpretations for this portion of the NW coast of Pangea. Both a heterozoan (cool-water) and photozoan (warm-water) association were identified on either side of a palaeogeographical high. Cool-water carbonates were located outboard or to the west of this high, an area influenced by upwelling waters. Inboard of this high, a warm, protected sea developed at about 20°N palaeolatitude during the Asselian and Sakmarian. This configuration and palaeolatitude is similar to that of Baja California, Mexico and the Sea of Cortéz, providing a good modern analogue for these deposits where warm-water carbonates grow at latitudes otherwise dominated by cool-water deposits. The warm sea provided a place for a photozoan association to develop during the Early Permian when the low-latitude NW coast of Pangea was dominated by cool-water carbonates.