Battle of Mindanao - Background

Background

The campaign for Mindanao posed the greatest challenge for the liberating American forces, primarily for three reasons: the island's inhospitable geography; the extended Japanese defenses; and the strength and condition of the Japanese forces, which contained the significantly remaining concentration of combat troops in the Philippines.

Like most of the Philippine Islands and other similar places the U.S. Army operated elsewhere in the Pacific, the geographical conditions of Mindanao, the second largest island in the Philippines, offered very little inspiration for soldiers who would have to fight there. It boasted a long and irregular coastline, the inland topography generally characterized as rugged and mountainous. Rain forests and numerous crocodile-infested rivers covered the terrain, the rest by either lake, swamp or grassland. These grassland regions—along with dense groves of abacá trees, source of hemp fiber—offer the worst obstacles which limit vision and sapping the strength of soldiers who would have to force their way through.

The few roads in Mindanao further complicated the problem of movement. Two of these, was the generously named Highway 1, which cuts across the southern portion of the island, from just south of Parang on Illana Bay in the west to Digos on the Davao Gulf in the east and then north to Davao. The other, Sayre Highway the main north-south road, starts at Kabacan, midway between Illana Bay and Davao Gulf, then runs north through the mountains of Bukidnon and Macajalar Bay (off Misamis Oriental Province) on the northern coast.

The strongest of the Japanese defenses were concentrated around the Davao Gulf area, which was heavily mined to counter an amphibious landing, and in Davao City, the island's largest and most important city. Artillery and anti-aircraft batteries extensively ringed the coastal shoreline defenses. Believing that the Americans would ultimately attack from Davao Gulf and also anticipating that they would be eventually driven from the city, the Japanese also prepared defensive bunkers inland behind its perimeter where they could retire and regroup, with the intention of prolonging the campaign as much as possible.