This Washington 157 yarder is mounted on a Tillman 4-axle self-propelled carrier with a Tillman 90' tower.
Tillman also added a big skyline drum up front, making this yarder a slackline unit. Tower had 6 guylines.
One of the great things about this setup is that all 4 axles steer- allowing the operator to 'crab' into a tight
landing. Jack Tillman was from Aberdeen, Washington and built lots of custom yarders, towers, and carriers.