About a tenth of a mile up the Rush Mountain Trail are the gated and locked openings to the workings of the Morning Star Mine. During the early 1890s, zinc mining was simple because rich smithsonite ore, containing up to 52 percent zinc, was easy to find. With pick and shovel, miners dug the lemon-yellow mineral they called turkey fat. By the late 1890s, the richer ores became scarcer, and miners had to dig deeper into the hillside. There they found amber-colored rosin jack, a sphalerite zinc mineral, in stratified beds, pockets, and fissures. By 1916, extracting the ore required more sophisticated tools and methods, including compressed-air drills and jackhammers, blasting with dynamite, and milling with concentration tables. Mining deeper also brought greater danger, and some miners died digging the ore, as remembered by Rush resident Nadine Goodall, whose father narrowly escaped a cave-in that killed one man. Today the unstable mines are gated to keep people out and allow bats in, and the abandoned mines have become important nurseries and hibernating places for bats, including Indiana bats.