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Gray wolf reintroduction and dispersal into the Northern Rocky Mountains and surrounding regions has prompted questions, not only about increased cattle depredation losses, but also about this threat on cattle distribution patterns and losses from increased stress. Threatened cattle may shift preference from high-quality foraging sites to sites perceived as safer from wolf depredation, with a lesser regard for foraging conditions.  It is likely these distribution shifts will adversely impact foraging efficiency, and coupled with the additional stress perhaps ultimately causing increased disease susceptibility, decreased calf weaning weights, poorer cow body condition, and lowered reproductive success.  Our study evaluates wolf presence effects on cattle distribution and consequent impacts on productivity.  A Before-After/Control-Impact Paired (BACIP) experimental design is used. Control study areas in Idaho (3) have high wolf presence while study areas in Oregon (3) are shifting from initially low to elevated wolf presence.  Paired Idaho and Oregon areas have similar topography, vegetation composition, wild ungulate prey bases, and livestock management.  Cows are tracked at 5-min intervals using GPS collars (10 per area) throughout the grazing season.  Wolf presence is monitored by GPS and radio tracking, trail cameras, and scat surveys.  High wolf presence can frequently expose cattle to potentially threatening interactions. Ten GPS-collared cattle in an Idaho study area encountered a GPS-collared wolf 783 times at less than 500m over the course of 137 days during the 2009 grazing season.  Preliminary results of data analysis suggest considerable overlap exists between cattle and wolf preferred sites, shifts in cattle grazing patterns.