The December 29-30, 1985, flow test of the State 2-14 well, also known as the Salton Sea Scientific drill hole, produced fluid from a depth of 1865-1877 m at a reservoir temperature of 305????5??C. Samples were collected at five different flashing pressures. The brines are Na-Ca-K-Cl-type waters with very high metal and low SO4 and HCO3 contents. Compositions of the flashed brines were normalized relative to the 25??C densities of the solutions, and an ionic charge balance was achieved by adjusting the Na concentration. Calculated Na/K geothermometer temperatures, using equations suggested by different investigators, range from 326?? to 364??C. The Mg/K2 method gives a temperature of about 350??C, Mg/Li2 about 282??, and Na/Li 395??-418??C. -from Authors