We study load balancing in wireless networks with a single class of traffic, focusing our attention on an important example, i.e., Wireless Sensor Networks. The analysis is based on the Wireless Minimum Cost Problem, an optimization problem that implicitly captures the effects of interference through the novel use of an arc cost function that depends on the amount of traffic flowing through nearby links. We present an algorithm that optimizes the flow by modifying the traffic along cycles constructed during an initialization phase. Its operation may be viewed as trying to satisfy Kirchhoff's Voltage Law on an electric circuit containing interferistors. It is robust, distributed, with minimal communication overhead, and converges quickly. Furthermore, when the traffic is elastic, the algorithm can be easily modified to also perform congestion control.