Social integration is considered beneficial for people's health. However, research shows mixed results for the older population and often lower social participation and related health-outcomes for rural areas, rendering rural-living seniors a potentially vulnerable group. This article explores current opportunities, challenges, and possible improvements for seniors' public social participation in the structurally weak and fast aging Uckermark county in northeastern Germany. With a mixed-methods approach, we geocoded public data on social clubs, conducted expert interviews, and applied a qualitative content analysis to gain insights into the structural conditions and social mechanisms of seniors' social participation in the Uckermark. Geocoding revealed that over 60% of the settlements have at least one social club and experts deemed the number of social activity offers sufficient. However, they reported challenges relating to declining physical health, poverty, infrastructural deficits, difficulties in outreach, a lack of motivation, conflicting relationships, regional mentality, and a struggle for sustainability. They suggested prioritizing rural seniors' lives in the political agenda, increased networking and sustainable reorganization of regional stakeholders, and providing tailored participation offers. The interviews highlight the interconnectedness of different groups and historically shaped socioeconomic developments in the rural community. Relating these results to international studies and aging theories, we conclude that there are common structural challenges in rural regions that foster seniors' social disengagement. However, dynamic and regionally specific relationships, norms, and preferences seem to play a major role in seniors' selective (dis-)engagement in public social activities and deserve greater attention in the provision and evaluation of participation offers.