Dolomite is mined underground by International Marble & Stone Company (Imasco) 600 metres south of Crawford Creek, 2.4 kilometres northeast of the Crawford Bay Post Office.
The Crawford Creek Dolomite mine is situated in a band of limestone and dolomite of the Lower Cambrian Badshot Formation which extends north-northeast from the head of Crawford Bay for at least 12 kilometres. The bed outcrops along the east flank of the Preacher Creek antiform, a tight, overturned, eastward closing fold cored by overlying gneiss, schist and amphibolite of the Lower Cambrian and younger Lardeau Group. Underlying quartzite and schist of the Hadrynian-Lower Cambrian Hamill Group outcrops along the flanks of the fold. At the mine site a foliation that possibly represents bedding strikes 010 degrees and dips 26 degrees west. Elsewhere the dip is much steeper.
The deposit is comprised of white, medium-grained dolomite containing scattered crystals of various metamorphic minerals, especially tremolite. The dolomite develops a brown staining on weathered surfaces. Numerous randomly oriented fractures occur with spacings of 10 to 15 centimetres. A sample of randomly collected chips from the quarry analysed 30.26 per cent CaO, 20.17 per cent MgO, 2.14 per cent insolubles, 0.77 per cent R2O3, 0.92 per cent Fe2O3, 0.021 per cent MnO, 0.012 per cent P2O5, 0.01 per cent sulphur and 46.37 per cent ignition loss (Minister of Mines Annual Report 1964, page 184).
Imasco initially quarried dolomite on the south side of Crawford Creek, 600 metres north of the current mine site during 1962 and 1963. In 1964 quarrying began at the current site. Underground mining began in 1969 in order to produce a cleaner product. Between 1962 and 1988 some 734,500 tonnes of dolomite have been mined. The dolomite is trucked to the company's plant in Sirdar where it is crushed and screened for a variety of products, mostly agricultural soil conditioner, as a component in stucco and roofing materials, and is white, ornamental aggregate rock.
Inferred reserves at Crawford Creek are 2 million tonnes of dolomite grading 20.17 per cent MgO (Mining in British Columbia 1988).