The PRAIRIE FLATS deposit occupies the lower reaches of the Prairie Creek valley. It is located within the Summerland municipal boundaries, immediately southwest of the town site. The area was once a marsh but has since been drained for agriculture use and residential development. The PRAIRIE SOUTH EDGE area is included with the PRAIRIE FLATS occurrence, but the uranium contained in the PRAIRIE SOUTH EDGE is not included in the PRAIRIE FLATS deposit because of its low grade.

The PRAIRE FLATS deposit was discovered in 1979 by D.G. Leighton & Associates Ltd. during a regional uranium reconnaissance program. Work prior to the uranium moratorium in 1980 consisted of systematic soil augering and bench extraction tests.

This is a postglacial fluviatile type of deposit where uranium occurs in a collector basin composed of organic-rich valley fill deposited by Prairie Creek. Upwelling of groundwater into organic-rich soils, topographic control, and concentration of uranium by evaporitic discharge and ion adsorption-reduction are the principal depositional controls.

The area is underlain by granodiorite of the Jurassic Okanagan Intrusions, which is unconformably overlain by a succession of Eocene epiclastic sediments, pyroclastic rocks, and alkaline lavas of the Penticton Group White Lake and Marron Formations.

The deposit occupies an area of approximately 37.0 hectares with an average thickness of 1.7 metres grading 0.0334 per cent uranium (Culbert, 1979). The estimated average density of the deposit is 1000 kilograms per cubic metre (Culbert, 1979), yielding a calculated quantity of 629,000 tonnes. The uraniferous layer begins at the surface. Ore reserves to a depth of approximately 2 metres are about 195 tonnes of uranium (230 tonnes of U3O8); it is estimated that uranium has accumulated at a rate of about 23 kilograms a year since glacial retreat (Canadian Journal of Earth Sciences Volume 21, 1984, page 561).

A contour map of the deposit showing variations in uranium grade identifies several areas with greater than 2.0 pounds (0.9 kilograms) U3O8 per square metre (Culbert, 1979). Cross-sections of the deposit, based on 28 auger holes, show high grade layers with greater than 0.1 per cent uranium (Culbert and Leighton, 1988, Figure 7). Molybdenum enrichment (up to 0.09 per cent) is also present (Culbert, 1988).

An adjacent area, known as the PRAIRIE SOUTH EDGE, occupies an area of approximately 10.8 hectares with an average thickness of 2.1 metres grading 0.0184 per cent uranium (Culbert, 1979). The estimated average density of the uraniferous layer in the PRAIRIE SOUTH EDGE is 1300 kilograms per cubic metre (Culbert, 1979). The uraniferous layer lies 1.2 metres below the surface (Culbert, 1979).