Drift distances of larval Pycnopsyche guttifer were determined from May through July 1975, on the basis of recoveries from 4100 larval cases marked with an acrylic pigment-epoxy mixture in a sequence of pools 1.5 km above the mouth of Factory Brook. Average drift distances for larvae released in May and early June ranged from 400-700 m before case attachment began in late June. Catastrophic drift after a rainstorm washed most larvae a considerable distance downstream. Three marked larvae, retrieved below the mouth of the stream, had traveled the 1.5 km in less than 25 days. No marked larvae were found upstream from their release pool. Directional movements of adults were determined by spreading a nondrying adhesive on nine house screens (three rows of three screens each} suspended over midstream and on six screens placed in trees adjacent to the stream. Captures on the midstream screens showed the number of females flying upstream to be significantly greater (p < .05) than the number flying downstream; directional movements of males were not significantly different. Adults collected on screens in the adjacent woodland exhibited no directional flight preference.