'Tigar 1C' was the Allied construction of a road between Ledo in the north-eastern Indian state of Assam and Kunming in the Chinese south-western province of Yunnan so that supplies could be carried by truck to the Chinese Nationalist forces of Generalissimo Chiang Kai-shek, thus obviating the need for the airlift operation over the 'Hump' of the eastern Himalayas (December 1942/31 January 1945).

Up to May 1943 the Allies had worked largely on the principle of reopening the Burma Road so that China-bound supplies could be delivered to Rangoon by ship and then moved by rail to Lashio, the Burmese end of the Burma Road to Kunming. From the time of the 'Trident' conference onward, however, the Allies began to reveal considerably more realistic opinions about the liberation of southern and central Burma, and all mention of the Burma Road was tacitly dropped in favour of positive opinion for a new supply road running basically to the south-east some 507 miles (816 km) from the railhead at Ledo in north-eastern Assam, across the mountains, jungles and swamps of northern Burma to Wanting in Yunnan, where it would link with the original Burma Road for the final 572 miles (921 km) to Kunming.

Pending the completion of this new road, the 'Trident' conference decided that the monthly airlift over the 'Hump' should be increased to 10,000 tons by the autumn of 1943 after an initial increase to 7,000 tons in July. In the event the July tonnage was a mere 4,500 tons, and continued difficulties were encountered in building up the tonnages for delivery to the Chinese forces and to Major General Claire L. Chennault’s US 14^th AAF, which had an ever-increasing demand as the war progressed.

Both the British and the Americans proposed plans for the Ledo Road, but the plan of Brigadier General Raymond A. Wheeler was chosen and responsibility was thus given to the Americans under Colonel John C. Arrowsmith and later of Colonel Lewis A. Pick. Work started on 25 December 1942 from Ledo with the object of building the first sector of the road, 103 miles (166 km) long, across the Pangsau pass at a height of some 4,500 ft (1370 m) to Shingbwiyang in the Hukawng valley. The road reached the border with Burma, 43 miles (69 km) from Ledo, on 28 February 1943, but then came essentially to a halt as a result of the difficulty of bringing in supplies and the onset of the monsoon. Only 3 miles (4.8 km) were completed between the end of March and middle of August, and Singbwiyang was reached in December 1943. From here the gravel-covered three-lane road advanced to Myitkyina and then crossed the Irrawaddy river to Bhamo, where it linked with the pre-war British road to Namkham, and then pushed forward to meet the Burma Road at Mong Yaw. Progress over the later stages was much dependent on the course of operations in northern Burma, but the Ledo Road was officially opened on 31 January 1945, and soon after this the combined Burma and Ledo Roads complex was renamed the Stilwell Road by Chiang.

By the time the new road had been completed, the 'hump' airlift over the Himalaya mountains had become massive in capability, and the war ended before traffic over the Ledo Road could begin to approach the levels of the airlift.