Complex sentence: During World War II, the field was overrun by rank grass, but still used by Col. Hipolito Garma's guerrilla 105th Division, as a re-supply base for Wendell Fertig's guerrillas, and as an emergency landing field.
Split into simpler sentences: During World War II, the field was overrun by rank grass. It was still used by Col. Hipolito Garma's guerrilla 105th Division, as a re-supply base for Wendell Fertig's guerrillas and as an emergency landing field.