Robot locomotion across complex terrain has been widely studied for cases where the robot is much larger than obstacles or when the obstacles are much larger than the robot (e.g. climbing). Less is known about locomotion in environments where obstacles are of similar size to the locomotor; the most studied schemes rely on vision to map the terrain for appropriate footholds. Here we take a different approach, augmenting the emergent high-performance capabilities of a compliant-legged robot with a simple controllable tail. The quadruped robot (L=27cm, m=2.8kg, limb length 8cm) uses a diagonal couplet gait to locomote at 0.15 BL/sec on flat ground. When challenged by a 160cm long 80cm wide terrain composed of blocks with heights chosen from an inverted Gaussian distribution centered around the limb length, the robot suffers failures consisting of limb jamming. Controlling the tail via periodic taps improves performance, allowing the robot to successfully traverse the terrain in 2/46 trials via controlled disturbances to decrease probability of jamming. Inspired by this, we implement a controller which senses high current draw associated with limb jams which further improves performance (3/25 trials successful).