Technical Abstract: Throughout the southern Ozark Highlands, endophyte-infected tall fescue [Lolium arundinaceum (Schreb.) Darbysh] hay often is stored outdoors, without cover. At two research sites (Fayetteville and Batesville, AR), the effects of unprotected storage were assessed for large-round bales of tall fescue hay packaged at three diameters (1.1, 1.4, and 1.7 m). Bales were stored over winter either inside or outside on wooden pallets, and then sampled at three depths (0-0.15 m, 0.15-0.31 m, and 0.31-0.46 m). At both locations, bale diameter had no effect (P > 0.05) on dry matter (DM) recovery or nutritive value. Generally, there was little deterioration of nutritive value during the storage period, regardless of treatment; however, some interactions (P 0.041) of storage location and sampling depth were observed at each location. Ruminal disappearance kinetics of DM exhibited some statistical differences (P 0.030) in response to treatment; however, their relative magnitude was generally small, and there was little evidence to suggest biological relevance. After storage, concentrations of ergovaline were not affected (P > 0.05) by baling treatment at Batesville (overall mean = 256 g/kg); however, this was a 27.3% reduction from the initial concentration immediately after mowing. At Fayetteville this reduction was even greater, falling by 79.4% between standing forage (539 g/kg) and samples taken from baled hay after storage (111 g/kg). At both sites, bales stored outside on wooden pallets exhibited relatively small changes in nutritive value, disappearance kinetics, and ergovaline at the bale surface relative to the internal portions of the bale.