Extensive potash deposits are found in the southern half of the Province of Saskatchewan. The potash ore is contained in a predominantly rock salt formation known as the Prairie Evaporites. The Prairie Evaporites deposits are bounded by limestone formations and contain the potash beds. Three potash deposits of economic importance occur in Saskatchewan: the Esterhazy, Belle Plaine and Patience Lake members. The Patience Lake member is mined at Colonsay. The particular beds mined at Colonsay and Esterhazy have a mining height of 11 and 8 feet, respectively.

Colonsay utilizes shaft mining. Traditional potash shaft mining takes place underground at depths of over 1,000 meters where continuous mining machines cut out the ore face and load it onto conveyor belts. The ore is then crushed, moved to storage bins and hoisted to refineries above ground. Mining at Colonsay is conducted within the upper portion of the Patience Lake Member using a room and pillar mining method.

The Colonsay Facility uses an underground room and pillar mining method to extract potash. After being transported along a network of conveyor systems to the shaft, it is hoisted to the surface for onsite processing.