Both Biosphere Reserves (BR) and UNESCO Global Geoparks (UGGp) are expected to add value to their regions. Because the two systems share many features, their complementarity is hard to discern where they overlap, and operating both can impose coordination burdens. This study examines the Hakusan region—the only site in Japan where a BR and a UGGp overlap—to clarify how the overlap was established, the coordination mechanisms between the two systems, and their complementary functions. We interviewed four practitioners involved in operating the two systems. Although overlap was not an explicit aim in Hakusan, co-locating the administrative offices established routines that mitigated resource conflicts and enabled collaboration. Complementarity was observed to arise from differences in personnel networks engaged by each system and from the distinct value framings of Hakusan within each designation. However, because the two designations only partially coincide in territory and mandate, coordination challenges remain.
