Project summary Social housing is known to promote welfare for nonhuman primates (NHPs). Rhesus macaques living in large outdoor corrals experience fewer episodes of diarrhea and lower wounding rates, and have less alopecia compared to those living in other housing types. Further, macaques born in corrals show less stereotypy when housed inside compared to those born in other housing. However, the corrals currently in use at the ONPRC have limitations, including being located relatively far from processing areas (which requires animals to be moved to those areas on trucks), solid walls that prevent animals from viewing their environment, and lack of areas for introducing or re-integrating animals into the group. This supplement will allow us to renovate the design to erect a new, innovative, half acre corral, which will allow us to increase our breeding population by approximately 50-60 infants per year. The plan described in this application expands existing housing with a half-acre corral tied to existing infrastructure (thus reducing the need to transport animals by truck); will provide animals with varied enrichment options (including the ability to visualize their environment through observation windows); and will contain an introduction area to facilitate animal reintegration. Together, the corral redesign proposed in this supplement will increase breeding capacity in support of research, thus enhancing the scientific endeavor while promoting animal welfare.