Deposits of hydromagnesite are contained within Recent sediments that occur on low swampy terrain along the Riske Creek drainage, south of the Chilcotin Road, centered on Lots 178 and 1188. The drainage system is partly dry annually.

The western deposit, within Lot 1188, is estimated to cover 0.65 hectares. White hydromagnesite 60 to 90 centimetres thick grades downwards to a brown clayey soil at a depth of about one metre.

The eastern deposit, in Lot 178, is estimated to be about 0.84 hectares. It is white to cream hydromagnesite to about 84 centimetres depth and grades into brown clay at 1.27 metres.

A composite sample from five drill holes from the western deposit graded 42.3 per cent MgO, 0.7 per cent CaO, 41.9 per cent CO2, 4.4 per cent SiO2, 1 per cent iron and alumina and 9.2 per cent water (Bulletin 4).