The colonial period in our nation’s history was characterized by an ignorance of its mineral wealth and a dependence upon Europe for most raw materials, especially essential metals. During the War for Independence, European supplies were cut off, and Yankee ingenuity had to make the most of local deposits of metallic minerals. It was not long before mines were in operation on several lead veins in the Connecticut Valley, yielding a supply of lead for the duration of the war. But the mines were small, and most of them were soon abandoned, remaining only as historical sites, or as collecting localities for the mineralogist. Five of these old deposits are still accessible: four lie west of the valley at Loudville, West Farms, Hatfield, and Williamsburg; an important one is situated east of the valley at Leverett. All are very similar in geology and mineralogy, yet each possesses its own individuality. The Loudville vein was worked intermittently as late as 1861. It follows a fault fracture between walls of gneiss, but at the southwest end of the vein some of the minerals are disseminated through the Triassic sandstone and conglomerate. This feature indicates that the sediments were unconsolidated at the time of mineralization. The fault zone resembles many analogous fissures which give forth hot mineral-bearing waters in the Basin and Range region of Nevada, for the charged waters have impregnated the sands which cover the fissures. The Loudville vein contains numerous well-formed crystals. Barite was the first mineral deposited, and it is readily recognized as a heavy, easily scratched substance with one set of cleavage planes at right angles to two others. Gray metallic galena and resinous cleavable sphalerite or zinc blende occupy much of the space between the barite plates. Hard hexagonal crystals or white masses of quartz coat and even replace the barite plates. Spike-shaped crystals of calcite and siderite line many of the cavities and coat the quartz. A patient search will be rewarded by the finding of other minerals, including pyrite, chalcopyrite, pyromorphite, wulfenite, malachite and azurite. The old shaft has been closed and the tunnel at the river level has collapsed, hence the only exposures are in the open cuts. The most interesting is the one at the south end, where the barite plates are disseminated through the sandstone. Another series of pits can be found easily about 100 yards west of the road to West Farms and about one mile north of the Loudville deposit. The vein attains a maximum width of three feet between walls of gneiss, and it occupies a fault fracture which seems to be continuous with the Loudville zone. Included in the vein are many fragments of a black phyllite resembling the Leyden argillite, as well as pieces of gneiss. The minerals are identical with those found in the Loudville deposit, but the specimens of quartz, galena and sphalerite are more spectacular.