To the east, Malheur Lake and the Malheur National Wildlife Refuge offers a veritable oasis amidst the arid range lands. The Refuge stretches 39 miles wide and 40 miles long, and is home to 320 bird species. Spring is the most spectacular season. Northern pintails and tundra swans begin to arrive followed by sandhill cranes and large concentrations of snow, Ross' and whitefronted geese. Waterfowl, shorebirds and songbirds hit high number peaks as well. As the flurry of migration settles, broods of trumpeter swans and other waterfowl can be seen on most Refuge ponds and migrant shorebirds congregate on mud flats and alkali playas. Activity increases again in the fall as migration begins. One of the Refuge's greatest attractions occurs when greater sandhill cranes "stage," or gather, in the southern Blitzen Valley. Also look for large flocks of ducks, Canada geese and tundra swans. Winter is the quietest season at the Refuge although a variety of raptors, including bald eagles and rough-legged hawks can be seen.