Conjointly with Schedule-Aware Bundle Routing (SABR), inter-regional routing support will be a key component for future interplanetary networks. Dividing the network into topologically or agency-based regions allows SABR to scale by reducing its scope to intra-regional forwarding. In its first formulation, inter-regional transmissions are handled via a gateway called a node passageway that is simultaneously a member of the two regions it bridges. This paper proposes a technique to support regional contact passageways that allows an arbitrarily high number of participating nodes compared to the legacy node passageway. A proof-of-concept of this approach and an evaluation of the regional structure is provided to highlight the feasibility of the concept and the networking performance increase when switching from a regional tree structure to a regional graph structure.