Into the West by Mercedes Lackey

Baron Valdemar and his people have found a temporary haven, but it cannot hold all of them, or for long. Trouble could follow on their heels at any moment, and there are too many people for Crescent Lake to support. Those who are willing to make a further trek by barge on into the West will follow him into a wilderness depopulated by war and scarred by the terrible magics of a thousand years ago and the Mage Wars. But the wilderness is not as empty as it seems. There are potential friends and rapacious foes….