The Mariposa mine in Brewster County, Tex., ranks second in all-time production of quicksilver in the Terlingua mining district. It is in Section 59, Block G-12, and is about 7 miles by road west of the Terlingua Post Office (see accompanying maps). The nearest railroad shipping point is Alpine, Tex., which. is 93 miles by road to the north. The mine is now controlled by the Esperado Mining Co. of Houston, Tex.
Since 1895 the Mariposa mine has produced between 20,000 and 30,000 flasks of quicksilver. The major production was before 1911, but the mine was active during the first World War, and again during the period from 1933 to 1942. In February 1944, the Esperado Mining Co, was reworking some of the old dumps and exploring an ore showing in the east wall of the Perry pit.
The productive ground, a rectangular area roughly 3,500 feet long and 1,000 feet wide, centers about California Hill (see plate 1). The principal subsurface workings, about 3 miles of drifts, stapes, and crosscuts, are under California Hill, but much of the ore was taken from numerous pits, trenches, and shafts northeast and west of the hill. Of the 121 shafts over 20 feet deep, 6 are over 100 feet deep and. 2 of these, No. 5 (or Cruz) shaft and the finite shaft, are 300 or more feet deep. The Contratiro winze (see map of workings) extends 200 feet below the 100 level of the mine. Several thousand feet of drifts and crosscuts extending from the deeper shafts explore the mineralized ground through a vertical range of about 300 feet, but almost all the ore that has been produced came from the uppermost workings.
