Short answers, pulled from the story.
The Chindwin River is a river in Myanmar and the largest tributary of the Irrawaddy, which is Myanmar's principal river. It originates in the Hukawng Valley of Kachin State and flows generally southward before joining the Irrawaddy. It is also known as the Ningthi River.
The Chindwin River begins where the Tanai, Tabye, Tawan, and Taron rivers converge in the broad Hukawng Valley of Kachin State. The Tanai's headwaters are on the Shwedaunggyi peak of the Kumon mountain range, about 12 miles north of Mogaung.
The Hukaung Valley Wildlife Sanctuary is a protected area established by the Burmese government in 2004 in the Hukawng Valley, through which the upper Chindwin flows. It was created as the world's largest tiger preserve, initially covering approximately 2,500 square miles, and was later extended to 21,800 square kilometers, making it the largest protected area in mainland Southeast Asia.
The Chindwin River served as a major military barrier during World War II. Allied forces under General Joseph Stilwell retreated on foot across the mountains west of the river into India after the Japanese cut off sea access, suffering heavily from disease and hunger. The river also blocked Japanese forces trying to invade India and Allied forces attempting to reoccupy Burma.
Imperial jade, also called jadeite, is found at Hpakant, located in the headwaters of the Uyu River, which is the largest tributary of the Chindwin. Hpakant is described as the only place in the world where this finest grade of jade is found.
Towns along the Chindwin River include Hkamti, Htamanthi, Homalin, Mawlaik, Kalewa, Kalaymyo, Mingin, and Monywa. Monywa is the largest city along the river's lower course, sitting at the boundary between the Sagaing and Pakokku districts.