Migratory Golden Eagles (Aquila chrysaetos) from Alaska winter across a vast region of western North America, much of which is undergoing rapid change from a diversity of indirect and direct human activities. To address recent conservation concerns, we are studying the year-round movements of migratory Golden Eagles from interior and northern Alaska to identify and evaluate potential risks to their survival. We are also developing new survey techniques to estimate population size and trends. As part of our ongoing studies, we observed migrating Golden Eagles in spring and autumn 2014 during field investigations to locate Golden Eagle capture sites in eastern interior Alaska, and in spring 2015 during capture activities. We observed large numbers of Golden Eagles in both spring and autumn, suggesting that the Mentasta Mountains are an important migration corridor for this species. Further, our observations, including 1364 migrating Golden Eagles in October 2014, suggested that the Alaska Golden Eagle population is much larger than is reflected in the only currently available statewide population estimate of 2400 eagles. In combination with historical and contemporary tracking studies, our observations in the Mentasta Mountains provide important new information about Golden Eagle migration in Alaska and stimulate interest in answering fundamental questions about using counts of migrating Golden Eagles to estimate, and detect change in, the population size of Alaska's migratory Golden Eagles. Our observations also provide new information about Rough-legged Hawk migration in Alaska.