The Tuff 7 occurrence is located at an elevation of approximately 1900 metres on an east-trending ridge north of Atteycelley Creek, approximately 11 kilometres northeast of the north end of Duncan Lake, and about 191 kilometres north-northwest of the community of Germansen Landing.

The Toodoggone Gold Camp lies within the eastern margin of the Intermontane Belt and is underlain by a northwest trending belt of Paleozoic to Paleogene sediments, volcanics and intrusions. Regionally, the area is situated within a Mesozoic volcanic arc assemblage bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins. Devonian to Permian Asitka Group crystalline limestones are the oldest rocks exposed in the region and are commonly in thrust contact with Upper Triassic Stuhini Group marine sedimentary and volcanic rocks, andesite flows and pyroclastic rocks. These units have been intruded by the granodiorite to quartz monzonite of the Early Jurassic Black Lake Suite and are in turn unconformably overlain by or faulted against dacitic volcanics and volcaniclastics of the Lower Jurassic Toodoggone Formation (Hazelton Group).

The dominant structures in the area are steeply dipping faults that define a prominent regional northwest structural fabric trending 140 to 170 degrees. High angle, northeast-striking faults (approximately 060 degrees) appear to truncate and displace northwest-striking faults. Collectively these faults form a boundary for variably rotated and tilted blocks underlain by monoclinal strata.

A major structural zone associated with the Saunders Creek regional fault cuts diagonally through the area, striking northwest. The geology of the area is separated into four northwest trending, fault-bound panels. The occurrence is underlain by the west-central panel, an upfaulted panel of regionally propylitic-altered Toodoggone volcanics in the south portion and Stuhini volcanics in the northern portion. A major north-northwest striking fault separates the hosting panel from structurally higher, zeolitized Toodoggone volcanics to the east. Stuhini Group volcanics are characterized by augite and plagioclase porphyry, basalt and andesite flows and breccias. Several members of the Toodoggone Formation are present. The Adoogacho Member, the lowest stratigraphic division, consists of reddish and mauve, variably welded ash flows and lapilli-ash tuffs with subordinate block-lapilli tuff, epiclastics and rare andesitic lava flows interbedded with ash-flow tuffs (Bulletin 86). These rocks are propylitically altered with argillic overprinting. The Moyez Member consist of grey to maroon conglomerates. The conglomerate contains 20 to 30 per cent by volume granite clasts averaging 4 centimetres in diameter.

Locally, no description of the mineralization is known but it is assumed to be similar to that of other occurrences in the area and consist of quartz-calcite veins with pyrite and chalcopyrite mineralization.

In 2004, a rock sample (185643) assayed 1.02 grams per tonne gold, 6.1 grams per tonne silver and 0.548 per cent copper, whereas two other samples (185647 and 185648) yielded from 5.2 to 9.1 grams per tonne silver and greater than 1.0 per cent copper, respectively (Assessment Report 27636). No sample descriptions were provided.

During 2003 through 2006, Stealth Minerals Ltd. completed programs of prospecting, geochemical (rock, silt and soil) sampling and geological mapping in the area as the Fog-Mess property.

During 2014 through 2017, Serengeti Resources Inc. completed programs of prospecting, rock, silt and soil sampling and a 9.0-line kilometre induced polarization survey on the area immediately south as the UDS property.