Specifications. 2684. Earthwork, concrete lining, tunnel, and structures for Horsetooth supply conduit, station 0+00 to station 53+88.94, Hnrsetooth Feeder Canal, station 53+70.25 to station 67+52.1, and access road, station 0+00 to station 14+76.7, Colorado-Big Thompson project, Colo.