This third volume of Yukon Geology represents five years of geoscientific research sponsored and funded by Exploration and Geological Services Division (EGSD). Under the Northern Mineral Policy, Indian and Northern Affairs Canada has the responsibility to develop ad maintain the geoscientific database. In support of this policy, EGSD has assisted the authors through direct funding or by logistical support during the field season. This volume covers a wide range of topics; the majority of papers have direct implications for mineral exploration in the Yukon.