Thanks Andy. The eagles seem to start their northward migration from here about the first of April. If one is standing outside along the river mid-morning when the migration starts one will see small groups (1, 2, or 3) seek thermals and gain altitude in the thermals. They break out of the thermal upriver and seek the next thermal. Their migration flight seems much more economical in motion and energy expenditure than their hunting flight.
I still haven't had any good opportunities to for in flight pictures but three of the last four days I've enjoyed seeing them hunt over the river near Lock & Dam 15 on my way to work.