Systems and methods employing a small gauge steerable catheter including a locatable guide with a sheath, particularly as an enhancement to a bronchoscope. A typical procedure is as follows. The location of a target in a reference coordinate system is detected or imported. The catheter is navigated to the target which tracking the distal tip of the guide in the reference coordinate system. Insertion of the catheter is typically via a working channel of a convention bronchoscope. Once the tip of the catheter is positioned at the target, the guide is withdrawn, leaving the sheath secured in place. The sheath is then used as a guide channel to direct a medical tool to target.