Battlefield Mars — David Robbins

Several centuries into the future, Earth has established three colonies on Mars. No indigenous life has been discovered, and humankind looks forward to making the Red Planet their own. Then 'something' emerges out of a long-extinct volcano and doesn't like what the humans are doing. Captain Archard Rahn, United Nations Interplanetary Corps, tries to stem the rising tide of slaughter. But the Martians are more than they seem, and it isn't long before Mars erupts in all-out war. BATTLEFIELD MARS, a novel of pulse-pounding suspense and breathtaking action.