A power machine (100; 200; 300; 400; 500) comprising: a frame (110; 210; 310; 410; 510); a cab mounted on the frame; a lift arm structure (230; 330; 430; 530) having a boom (234; 334; 434) pivotally mounted to a tower proximal a front end of the frame at a pivot connection (392; 394) position substantially forward of the cab, the lift arm structure having a telescoping arm (236; 336; 436) coupled to the boom and configured to extend from and retract into the boom; an implement interface (270; 3 70; 4 70) coupled to a distal end of the telescoping arm of the lift arm structure and configured to mount an implement (376; 476) to the lift arm structure; a first actuator (238; 335; 435) coupled between the boom and the frame and configured to raise and lower the boom; a second actuator coupled between the telescoping arm and the boom and configured to extend and retract the telescoping arm relative to the boom; a control system (160; 260; 360; 460) including a controller configured to control the first and second actuators during a lift operation such that the first actuator raises the boom pivotally mounted to the tower proximal the front of the frame and such that the second actuator extends and retracts the telescoping arm to maintain a substantially vertical path of the implement interface or the implement attached to the implement interface throughout the lift operation; and a first sensor configured to provide an output indicative of a position of the boom relative to a reference and a second sensor configured to provide an output indicative of a position of the telescoping arm relative to the boom, and wherein the control system is further configured to control the first and second actuators during the lift operation as a function of the outputs of the first and second sensors. a frame (110; 210; 310; 410; 510); a cab mounted on the frame; a lift arm structure (230; 330; 430; 530) having a boom (234; 334; 434) pivotally mounted to a tower proximal a front end of the frame at a pivot connection (392; 394) position substantially forward of the cab, the lift arm structure having a telescoping arm (236; 336; 436) coupled to the boom and configured to extend from and retract into the boom; an implement interface (270; 3 70; 4 70) coupled to a distal end of the telescoping arm of the lift arm structure and configured to mount an implement (376; 476) to the lift arm structure; a first actuator (238; 335; 435) coupled between the boom and the frame and configured to raise and lower the boom; a second actuator coupled between the telescoping arm and the boom and configured to extend and retract the telescoping arm relative to the boom; a control system (160; 260; 360; 460) including a controller configured to control the first and second actuators during a lift operation such that the first actuator raises the boom pivotally mounted to the tower proximal the front of the frame and such that the second actuator extends and retracts the telescoping arm to maintain a substantially vertical path of the implement interface or the implement attached to the implement interface throughout the lift operation; and a first sensor configured to provide an output indicative of a position of the boom relative to a reference and a second sensor configured to provide an output indicative of a position of the telescoping arm relative to the boom, and wherein the control system is further configured to control the first and second actuators during the lift operation as a function of the outputs of the first and second sensors.