—Hybrid networks are a promising architecture that builds ad hoc, wireless networks around the existing cellular telephony infrastructure. In this paper we present DST, a routing protocol for hybrid networks that is scalable with the network size and achieves high throughput by taking advantage of multiple channels. DST maintains a close to optimal spanning tree of the network by using distributed topology trees. DST is fully dynamic and generates only O(log n) messages per update operation. We show experimentally that DST scales well with the network size, making it ideal for the metropolitan environment hybrid networks are expected to operate in.