The goal of the proposed project is to understand rural-urban disparities in cognitive aging and how the social environment influences development of Alzheimer’s disease and related dementias (ADRD) in later life. We propose to gather two waves of surveys and ecological momentary assessments to characterize the mechanisms underlying relationships between personal social networks, face-to-face interactions, activity spaces, and cognitive symptoms of ADRD in older adults living in urban and rural areas. Rates of ADRD are disproportionately high among older adults in rural areas compared to those in urban areas. A critical point of intervention is the social environment, which has the potential to reduce these geographic disparities by offering opportunities for cognitive stimulation. For instance, stimulating social interactions and activities (e.g., number of network friends, frequency of social contact, and participation in social events) have been identified as promising avenues for interventions to develop resilience against ADRD. However, the existing literature relies on limited and unidimensional measures of the social environment. We adopt a multi-method approach to identify which aspects of the social environment best explain rural-urban cognitive aging disparities. Our specific aims are as follows: Aim 1 is characterize the daily social interactions and activities of older adults in rural and urban areas. Aim 2 is to assess how a combination of personal networks, social interactions, and activity spaces either mediate or moderate the relationship between geographic residence and aging-related cognitive impairments linked to ADRD. Aim 3 is to explore longitudinal relationships between changes in the social environment and aging-related cognitive impairments among rural and urban older adults. By combining leading-edge methods from the social sciences—including social network analysis and ecological momentary assessments—this project seeks to identify novel targets for assessment and intervention to reduce the burden of cognitive aging on individuals, families, and the health care system across rural and urban areas. This knowledge is critical for identifying effective social intervention targets for reducing risk of ADRD in rural and urban areas.