Black water has been found in 18 boreholes drilled since 1949 in an area around Farson and Eden in the northern Green River Basin. The black water is produced from unusually porous and permeable oil shales of variable richness in the Wilkins Peak member of the Green River Formation. The black water color is caused by organic acids dissolved in a sodium carbonate solution. Because of minimal information, the explanation for the occurrence of the porosity, permeability, and the presence of black water in a usually impermeable shale is difficult and requires further study. However, in our opinion the black water is original lake water incorporated in the sediments in a low place in the lake bed during recessions of the lake. Further deposition created closed aquifers which, when penetrated by drilling, produce artesian water due to overburden pressure rather than to the more common mechanisms of gas pressure or hydrodynamic drives. Since 1949, attempts have been made to produce the water for economic exploitation, but no economic use has yet been made of it.