This invention provides an apparatus for mounting, driving and steering the wheels of a high mobility wheeled vehicle, such as those used over roadless terrain in tree harvesting operations. Each vehicle wheel is mounted on a rotatable hub which is in turn journaled on the end of a wheel drive housing. The housing is medially pivoted to the wheel suspension structure of the vehicle for steering movements and has a driving motor mounted on the inner end of the housing and connected to the wheel hub through an appropriate gearing system. The pivotal mounting of the drive housing is preferably located at the end of a walking beam arm which is disposed at a substantial horizontal angle with respect to the longitudinal axis of the vehicle to provide clearance for steering movements of the vehicle wheel. The steering motion is imparted to the drive housing by an actuator which is connected between the inner end of the drive housing and the inner end of the walking beam arm.