In the middle foothills and valleys of the southern slopes of the Himalayas live tribes, among which a very old form of Shamanism mixed with elements of Buddhism and Hinduism is still predominant today. These tribes, the Gurung, Magar, Tamang, etc., have an old mask tradition. Shamans and special dancers perform there with masks and costumes during ceremonies, theatrical performances and dances. These masks are usually crudely carved out of hardwood and age considerably while hanging in the rafters of the smokey huts in which many Nepalese live. The resulting patina is very appealing to collectors.
This Middle Hills mask is on page 39 of Masks of the World by Robert Ibold with Troy Yohn.