Movements and survival of immature Laid eagles (Haliacetus leucocephalus) beyond their first winter remain largely unknown, and lack of information may impede strategies for effective conservation. We analyzed encounters, sightings, and radio detections of bald eagles auxiliary marked as nestlings in the Greater Yellowstone Ecosystem (GYE) between June 1979 and July 1987 to determine movements, survival, and role of Yellowstone National Park in the ecology of CTE bald eagles. Of 344 bald eagles Landed, 17% were encountered to June 1998. Most (84%) were encounters of bald eagles >1 year old. Half of encounters were external to the GYE and occurred in 7 western states and 1 Canadian province. All sightings of color-landed bald eagles (n = 76) were of bald eagles >1 year old, and 76% occurred in the GYE. Location and timing of encounters and detections of radiotagged bald eagles indicated most (>90%) juveniles left the GYE in autumn, traveled as far west as coastal stales to winter, and returned to natal areas the following spring. Natal dispersal appeared female-biased, and bald eagles produced in the GYE recruited into breeding populations both in and out of the ecosystem. Mortality of 49 bald eagles recovered was from unknown causes (31%), electrocution or collision with power lines (20%), known or suspected poisoning (16%), and gunshot wounds (14%). Eighteen percent was distributed among 3 other causes. Recovery rates indicated Laid eagles 3-5 years old experienced the highest mortality Kaplan-Meir analysis of detections of radiotagged Laid eagles indicated first-lear survival of 87%, followed by a constant decrease in survival rate over 7 years. Survival estimates determined by radio-tracking were consistent Midi Land recovery results in illustrating low survival in 3- to 5-year-old age classes. Radiotracking of immature bald eagles suggested habitat in Yellowstone National Park was important in promoting survival of eventual recruits to the GYE population.