CHAPTER II

Birth Of A Tradition

The lay of the land and the guerrilla nature of Viet Cong warfare in South Vietnam demanded that the American forces stationed there from the early 1960s through March 1973 again use the medical helicopter. In a country of mountains, jungles, and marshy plains, with few passable roads and serviceable railroads, the allied forces waged a frontless war against a seldom seen enemy. Even more than in Korea, helicopter evacuation proved to be both valuable and dangerous.

South Vietnam consists of three major geographic features. A coastal plain, varying in width from fifteen to forty kilometers, extends along most of the 1,400 kilometers of the coast. This plain abuts the second feature-the southeastern edge of the Annamite Mountain Chain, known in South Vietnam as the Central Highlands, which run from the northern border along the old Demilitarized Zone south to within eighty kilometers of Saigon. The Central Highlands are mostly steep-sloped, sharp-crested mountains varying in height from 5,000 to 8,000 feet, covered with tangled jungles and broken by many narrow passes. The southern third of the country consists almost entirely of an arable delta.

These three geographical features helped shape the four military zones of South Vietnam. The northern zone, or I Corps Zone, which ran from the Demilitarized Zone down to Kontum and Binh Dinh provinces, consisted almost entirely of high mountains and dense jungles. At several points the Annamites cut the narrow coastal plain and extend to the South China Sea. II Corps Zone ran from I Corps Zone south to the southern foothills of the Central Highlands, about one hundred kilometers north of Saigon. It consisted of a long stretch of the coastal plain, the highest portion of the Central Highlands, and the Kontum and Darlac Plateaus. III Corps Zone ran from II Corps Zone southwest to a line forty kilometers below the capital, Saigon. This was an intermediate geographic region, containing the southern foothills of the Central Highlands; a few large, dry plains; some thick, triple-canopy jungle along the Cambodian border; and the northern stretches of the delta formed by the Mekong River to the south. IV Corps Zone consisted almost entirely of this delta, which has no forests except for dense mangrove swamps at the southernmost tip and forested areas just north and southeast of Saigon. Seldom more than