In 1894, prior to the construction of the steel dam, the Atlantic Mining Company built a timber crib dam across the Salmon Trout River. The dam created a reservoir which supplied water to the Atlantic stamp mill which extracted copper from ore-bearing rock. With the growth of the Atlantic stamp mill and the construction of the Baltic Mining Company mill nearby, this reservoir proved to be insufficient, and in 1901 the steel dam was built. It was designed by J. F. Jackson and built by the Wisconsin Bridge and Iron Company. The old timber crib dam remained in place, submerged, upstream of the steel dam. A system of spillways, sluices (or "launders" as they are referred to in contemporary texts), and pipes brought water downhill to the stamp mills. The dam itself measures 74 ft (23 m) high at its center and extends for a length of 1,006 ft (307 m) across the river. Access to the reservoir was shared by the Atlantic and Baltic mines, which had a common board of directors.