The western highlands (sometimes called the central highlands to distinguish from the mountainous regions of North Vietnam) in South Vietnam are located in the central part of the country, along the borders with Laos and Cambodia. It’s rugged country, mountainous and in places barren. Many of the inhabitants are not Vietnamese but tribesmen called Montagnards by the French (meaning mountaineers or mountain people). They are quite different ethnically from the Vietnamese who have historically persecuted them. For more on these people see http://factsanddetails.com/southeast-asia/Vietnam/sub5_9d/entry-3395.html
Key developments in Last of the Annamese take place in the highlands. Thanh invites Chuck to travel with him on a visit to Pleiku and Ban Me Thuot. In Pleiku, they meet the commander of II Corps, General Tran van Tri, who refuses to believe that the North Vietnamese are about to launch an offensive. Thanh and Chuck then immediately fly south to Ban Me Thuot where they know that the first strike will occur. The attack takes place while they are still there, and they take off in Thanh’s C-47 just as the airstrip comes under fire.
I spent a good deal of time in the highlands during the sixties and returned there with my counterpart, a South Vietnamese general, in early March, 1975. Our trip closely paralleled Chuck and Thanh’s trip as told in the novel, including the takeoff just as the airstrip was raked with bullets.
Thanh takes Chuck to the highlands to test him before ceding his son, Thu, to Chuck’s care. The trip tested me, too. That travel, and the fall of the highlands shortly thereafter followed by North Vietnamese seizure of the northern half of South Vietnam, persuaded me that the end was near in Vietnam. And I learned that I had the stamina to withstand the final collapse.