This paper proposes a fast and reliable routing protocol (FaReli) for multi-channel, multi-hop cognitive wireless sensor networks (CRSNs). Being aware of the spectrum dynamics in the CRSN, a framework is proposed to estimate the remaining duration of spectrum availability which is based on the expected idle length of channels, sensing period, and communication history on the channel. Specially, in combination with the per hop delay analysis, the routing path from sources to the sink can be established such as it provides a shorter delay and reliable communication. Simulation results are conducted to demonstrate that the proposed routing algorithm based on spectrum and delay analysis potentially improve the network performances in terms of throughput, delay.