The long range wide area network (LoRaWAN) forms a star topology where end device (ED) sends data to network server (NS) through gateway (GW). It requires a GW to be connected to the NS through an IP network as the backhaul link. However, when a LoRaWAN is deployed in a remote area, such connection may not be possible. Thus, it is important that the GW can reach the NS through multihop GW-to-GW (G2G) communication using LoRa technology. To realize it, we propose a multihop G2G communication protocol for LoRa networks. The proposed protocol includes both routing protocol and channel access scheme. A packet aggregation feature is also added for improving the transmission efficiency of GW. The simulation results demonstrate that the proposed protocol successfully enables multihop G2G communication for LoRa networks with reasonably good performance.