Strata underlying the Baltic, from oldest to youngest, include: conglomerates and coarse clastic sediments of the Upper Proterozoic Toby Formation (Windermere Supergroup); slates, quartzites, grits and conglomerates of the Upper Proterozoic Horsethief Creek Group; dolomites of the Cambrian Jubilee Formation; argillite and dolomite of the Cambrian to Ordovician McKay Group; dolomite, shale, sandstone and quartzite of the Ordovician to Silurian Beaverfoot Formation; and argillite, argillaceous limestone and quartzite of the Devonian Mount Forster Formation.

Fossiliferous dolomite and sandy dolomite overlie Jubilee dolomites and Horsethief conglomerates. Pyrite, galena, sphalerite and smithsonite occur in fossiliferous dolomite breccia at the base of a cherty clastic unit of the Beaverfoot Formation.

In 1975, operator Cominco Limited collected 500 soil samples, drilled 7 diamond-drill holes totalling 539 metres and performed unspecified rotary drilling, mapping and road construction. In 1978, owner Gordon Larrabee drilled one hole totalling 148.7 metres. In 1990, Cominco did some mapping on the Baltic property, owned by A. Louie, but most of the investigation appeared to be on the south side of the Forster Creek on the newer Baltic 10 claim showings (082KNE047).