A combination trencher () and vehicle () is disclosed wherein the tractor () has a pair of mounting rods () and a mechanically driven transfer case () with a rotating hub () extending from the front of the vehicle. The trencher () has a frame () which includes two generally parallel mounting members () sized and shaped to receive the mounting rods () of the tractor (), and a hydraulic digging attachment (). The digging attachment () has a pivotal cutting boom (), an endless loop digging chain (), a hydraulic boom actuator (), and a hydraulic chain drive (45). The hydraulic chain drive () includes a hydraulic motor () mounted to the cutting boom () which drives the digging chain (). The hydraulic motor () is in fluid communication with the hydraulic pump () through a hydraulic control system ().