Multicast communication over mobile ad hoc networks has become popular. However, dependable and scalable multicast routing is required for mobile ad hoc networks even though network size and node mobility continue to increase. Therefore, this paper proposes a new hierarchical multicast routing scheme for such ad hoc networks. The proposed scheme introduces the inter-cluster group mesh structure based on our previous autonomous clustering proposal. In the proposed scheme, data packets are delivered from the source node to the multicast members through multiple routes over the inter-cluster group mesh structure. Simulations show that the proposed scheme is scalable with regard to network size and strong against node mobility; it can provide dependable multicast communication on large mobile ad hoc networks.