Angel Hot Spring is above the McCullough road in the canyon section of Klo Creek drainage basin, approximately 300 metres below the Kettle Valley railway cut, on the lower northern slope of Little White Mountain.

The area is underlain by gently dipping Shuswap gneiss and schist and small outliers of Chilcotin basalt accompanied by criss-crossing feeder dikes. The basalts range in age from Miocene to recent history and these rocks and associated fissures are believed to be a geothermal source. The area is within a region of high geothermal potential that includes much of the central and southern parts of the Okanagan Valley that is characterized by geothermal gradients ranging up to 70 degrees Celsius/kilometre.

Over a long period of time the stream has built a large mound of tufa 300 metres long, 150 metres wide, and up to 8 metres thick along the bottom of the valley of Angel Creek. The deposit consists of grey to brownish, crudely bedded, cellular carbonate tufa (travertine), forming successive lenses, each ranging from several centimetres to more than a metre thick, intercalated with gravel, logs, standing tree trunks, branches and twigs. The numerous cavities in the tufa are mostly the casts of twigs, sticks and other decaying or decayed and dissipated organic debris.

Analyses of the tufa obtained from 5 samples, collected from the length of the mound, show a range in CaO from 51.92 to 53.88 per cent, MgO from 0.26 to 0.44 per cent, Fe2O3 from 0.09 to 1.03 per cent, Al2O3 from 0.06 to 0.43 per cent, and SiO2 from 0.37 to 1.73 per cent. There is a slight increase in Si02 and Fe2O3 distally from the spring and an overall decrease in Al2O3. In general the composition is similar to the Clinton tufa deposit. X-ray diffraction analyses of the 5 samples (courtesy of Jim McLeod of the Cominco Laboratory, Vancouver, B.C.) indicate that the predominant mineral in the tufa is calcite.