Sony HX200V---These migrating Greater White-fronted Geese were on their way out to sea, to complete the great polar circle route to their northern nesting grounds. They may have begun this journey from the Gulf of Mexico. They used the airflow that comes up the western slope of the Cascade Mountains, to help them climb to an elevation of more than 11,000 feet and 10,600 feet AGL. There were about 200 of them and the many thousands of them in this population, fly in flocks of about 50 to several hundred.
Notice how their wingbeats are slow and shallow and they often glide for long distances. They can probably cover another 100 miles, slowly giving up altitude as they conserve energy with this style of flying, before they have to work their wings harder. The high mountains that may seem like an obstacle to their migration, are actually a help to them. Their routes are plotted to take advantage of geographical features like this.
Shot in AVCHD 60p at 28 Mbps and uploaded in that format. The lens was at full zoom, with the equivalent of 1,250mm and 44X, using the Active stabilization mode.