The poster showers two soldiers and an officer of the People’s Liberation Army, who appear to be Chinese, on horseback alongside members of a local militia unit, dressed in furs. The caption identifies the region as part of China’s “northwestern border region”, and the members of the militia unit appear to be Tibetans.
The reference to China’s northwestern border suggests the poster is connected to or was issued by military units which were stationed by the Northwest Military Bureau in far western areas of Tibet such as Shigatse and Ngari. Until 1980, western Tibet was under the administration of the Xinjiang division of the Northwest Military Bureau, based in Urumqi, while the other parts of Tibet were under the Southwest Military Bureau, based in Chengdu.
The date of the poster is unknown, but could be 1960s.