From 2003 to 2007, we intensively sampled 6 sites on an elevation gradient along the river in American Fork Canyon leading up to the base of Mount Timpanogos. Malaise traps and Lingren Funnels were collected 2 to 4 times a month and sorted for EPT and Diptera. Using this data, we are investigating the validity of the Mid-Domain Effect (proposed by Robert Colwell) along the riparian corridor. Sarah Judson focused her honors thesis on community similarity and the Mid-Domain Effect in the Ephemeroptera, Plecoptera, and Trichoptera (EPT) popultions. Elizabeth Bankhead is cataloged the Diptera with a particular emphasis on Empididae and compared these results to trends with EPT.