The occurrence of sulphur in the vicinity of Rustler Springs in northeastern Culberson County, Texas, has been known since 1854 when, according to Phillips (1902, pp. 13, 71), the mineral was recognized by William P. Blake, a geologist attached to a U.S. War Department expedition making a survey of a railroad route from the Mississippi River to the Pacific Ocean. In the latter part of the 19th century and first part of the 20th century the Rustler Springs district was regarded as a favorable potential source for domestic supplies of native sulphur. � The purpose of the present report is to review briefly the geology of the Rustler Springs district, describe the occurrence of some of the acidic sulphur earth deposits, insofar as that is possible at their present state of exposure, and discuss some of the economic aspects involved in production of mineral fertilizer from these deposits. The report is based upon a review of the available literature and short field examinations made by the writer during 1942, 1943, and 1946 and should be regarded as a progress report.