Geochemical investigations of lignite mine spoils ranging in age from 10 years to over 35 years were performed at an abandoned mined land reclamation project near Rockdale, Milam County, TX. A primary objective was to determine the degree to which oxidation of pyritic material had progressed for the design of an appropriate reclamation plan. For this purpose, eight continuous cores were recovered from the project area. The results indicated that within 10 years, consistent trends 157