The Tulameen Gypsum occurrence outcrops along the northeast bank of the Tulameen River, in the vicinity of the Princeton-Tulameen road and the Kettle Valley railway, about 1.6 kilometres downstream from Granite Creek.

The showing is comprised of a number of small, discontinuous deposits of powdery or solid gypsum. The gypsum is deposited on boulder clay, gravel or slide rock as a precipitate of Recent age. Some of the material is quite pure, while some is mixed with clay and gravel. Trenching on the various deposits has encountered thicknesses of 1.2 to 3.0 metres. The largest deposit covers an area 120 metres long and 30 metres wide, with a thickness of about 1.8 metres.

A few tonnes of gypsum were shipped to a cement plant in Princeton in 1913.