The annual winter bird migrations to the Bosque del Apache National Wildlife Refuge may not be the world's largest by sheer numbers, but the density is unreal: Some 13,000 sandhill cranes and 40,000 snow geese crowd the sky above small, flooded fields on the Rio Grande from November to February. Equally dense are the crowds of camera-toting visitors. But don't be intimidated by the hardcores, with their camo-cloaked 600mm lenses. The viewing platforms at the Bosque are often close enough to the flock to use a wide-angle. The refuge opens 30 minutes before sunrise, which is just enough time to set up before the morning fly-out. Chief of visitor services Shawn Gillette also recommends visiting in the spring and summer, when the southern migrationbirds flying north for the southern winterdelivers colorful neotropical flycatchers and tanagers. Stay at any of the budget motels in nearby Socorro, some 75 miles south of Albuquerque.