Mountain top removal/valley fill mining has become a widespread method of coal extraction in the southern and central Appalachians. This form of mining removes several hundred feet of overburden to access a coal seam and then deposits overburden into adjoining valleys and streams. In an attempt to understand the possible ramifications of mountain top removal/ valley fill mining on stream ecosystem function and structure, we are measuring leaf breakdown rates and macroinvertebrate diversity in five mined and five reference streams in the Gualey River basin in southern West Virginia. Because these mined streams drain fills of various ages, we hope to gain some insight into the different patterns of ecosystem process and structure between filled and reference streams. Packs of red maples (Acer rubrum) and white oak (Quercus alba) were installed in the 10 streams in December 2007, and replicate packs of each species are retrieved monthly until May 2008. In the lab, leaves are washed of sediments, and macroinvertebrates from packs are sorted, identified and counted. Breakdown rates and macroinvertebrates abundance will be compared between mined and reference sites using ANOVA.