Cleveland District
Note: not located on district map
Near Cleveland (T. 12 N., R. 40 E.) there is an unorganized district (not shown on Plate 1) in which manganese deposits have been prospected since 1922 and from which some ore has been shipped. The manganese occurs as layers of wad, with local nodules of mixed psilomelane and pyrolusite, interbedded with fine sand forming a terrace of probable lacustrine origin, whose top is at an elevation of 5,500 feet, regarded as of early Pleistocene age. From January 25, 1926, to May 5, 1927, 1,200 tons, ranging from 36.5 to 48 per cent manganese (dry basis) were shipped. Later data on production are given in Mineral Resources. The deposits at Lava Hot Springs are probably similar.
Fort Hall District
Commodities: copper, gold
This district (which includes what is sometimes termed the Portneuf) is extensive but contains only two lode mines that have produced. Each of these, the Moonlight and the Fort Hall, have shipped a few tons of copper ore. The district is crossed by the Union Pacific Railroad and by highways. The deposits are irregular replacements along fractures in Ordovician(?) sedimentary rocks containing chalcopyrite. pyrite, a little galena, and secondary sulphides in a gangue of quartz and calcite. In the Fort Hall district, gold placers have been worked to some extent along the flood plains of the Snake River. A little prospecting for lead is reported.
Swan Lake District
Commodity: lead
This little developed district, whose boundaries have not been accurately ascertained, is near the town of Swan Lake in southeastern Bannock County. Swan Lake is on the Union Pacific Railroad. The Chatterton lead mine at Swan Lake is reported to have workings totaling about 212 feet. Sulphur also occurs near here.
