The Hayes and Vittoni coal prospect outcrops 300 metres southwest of Holmes Creek, 1.4 kilometres northwest of the creek's confluence with Granite Creek and 15.5 kilometres west-northwest of Princeton.

The deposit occurs in the southern part of the Tulameen Basin, along its northeastern margin. This structural basin is comprised of a northwest-striking syncline that preserves a sequence of sedimentary rocks with lesser intercalated volcanics of the Eocene Allenby Formation (Princeton Group), up to 840 metres thick. The sequence rests unconformably on a basement of Upper Triassic Nicola Group metamorphosed volcanics and sediments. In the southern part of the basin, the syncline is asymmetric with the dips being approximately 45 degrees and 20 degrees on the northeast and southwest limbs, respectively.

The prospect is hosted in a coal-bearing shale member, approximately 130 to 200 metres thick, underlain by up to 120 metres of sandstone, siltstone and andesitic volcanics, and overlain by 580 to 700 metres of sandstone and pebble conglomerate, with interbeds of shale, ash and coal in the lower sections.

Three adits totalling 49 metres in length and three trenches expose six seams of coal interbedded with clay and shale, and minor sandstone. The beds strike 111 to 115 degrees and dip 45 to 60 degrees south. The best section occurs in the No. 1 adit, which contains 0.81 metre of coal, overlain by 0.30 metre of dirty coal and rock, followed by 1.68 metres of coal (Minister of Mines Annual Report 1946, page 241). The various other seams are 0.9 to 1.2 metres thick.