The Denis barite prospect is situated immediately northeast of the Alaska Highway, 3 kilometres northwest of the settlement of Fireside. It is centred on a barite vein at the common corner of the Denis 13 to 16 claims (Assessment Report 4483, Maps 1, 2).

The area is underlain by predominantly Lower Paleozoic sedimentary rocks of Ancestral North America (Geological Survey of Canada Maps 1712A, 1713A). Relief here in the Liard Plain is generally quite low and exposure is limited, so detailed geological control is lacking. The Denis property apparently consists of Cambrian (or possibly older) black to pale brown, thinly bedded siltstones that are gently to moderately folded into west-northwest–trending anticlines and synclines (Assessment Report 4483; Geological Survey of Canada Map 46-1962).

Mineralization consists of a barite vein that appears to be structurally controlled by a major anastomosing fault and breccia zone. The strike of the vein and zone varies from 240 degrees in the west to 268 degrees in the east, and it dips steeply. Bedding in the host siltstones changes from one side of the vein to the other: to the north it strikes 050 degrees and dips 80 degrees southeast, and to the south it strikes 100 degrees and dips 40 degrees south.

The vein system, designated the Number 1 vein, is 300 metres long and exposed in a series of 10 bulldozer trenches (Assessment Report 4483). The better and thicker sections are towards the west, where a zone of massive barite, 4 metres wide, is exposed in trench number 1. Scattered blebs of galena and chalcopyrite are associated. In trench number 2, located 30 metres to the east-northeast, the vein comprises four separate mineralized zones, the widest being 1.8 metres. A smaller, 0.75-metre wide barite vein is particularly pure, and is flanked by breccia containing blebs of chalcopyrite and malachite. Still farther east, the vein continues to become weaker, and only narrow barite veins are present.

A lead soil anomaly is present about 300 metres northeast of the barite vein system.

In 2013, a small prospecting team working on behalf of Fireside Minerals Ltd. confirmed the location of three of the original trenches, confirmed the dimensions and geometry of trench 1, and collected grab samples. They were not able to identify a causative body of a local lead-in-soil anomaly, which tracks north of trench 1 for approximately 850 metres (Assessment Report 34414).