The Nakina River occurrence is located near the area of the confluence of the Nakina River and Horsefeed Creek, about 69 kilometres southeast of the community of Atlin.

Limestone of the upper Mississippian to Permian Horsefeed Formation (Cache Creek Complex) underlies an extensive area stretching for 35 kilometres northeastward along the Nakina River and extending for up to 25 kilometres southeastward from the river to just southwest of Nakina Lake. Overlying chert and argillite of the Mississippian to Triassic Kedahda Formation (Cache Creek Complex) forms some of the higher peaks in the region. A few lenses of mafic flows and tuffs are present within the limestone. The unit is estimated to be 1500 metres thick in this region. Near Nakina Lake, the strata are warped into a series of large northwest-trending folds.

The Horsefeed Formation is comprised mostly of a limestone member at least 900 metres thick. This bed is composed of pale grey to pale buff grey, massive, fine grained, porcelaneous, crinoidal and foraminiferal calcarenitic limestone that is rarely dolomitic. Oolites and chert nodules are also quite rare. The member is overlain by 180 metres of well bedded, pale grey to dark grey, very fine-grained detrital limestone and dolomitic limestone. This member is in turn overlain by foraminiferal, calcarenitic limestone of upper Permian age.