You make your way in darkness, positioning yourself by the vast pool as the first light of dawn reveals distant mountains on the opposite, eastern side. You still can’t see them, but you can hear their calls, and on a good morning, when their numbers are high and they’re nearby, the sound is amazing. If something spooks them, the sound can be deafening: tens of thousands of Snow Geese rise and call out in enormous swirling clouds. You won’t forget the sound. If they fly low overhead, you can hear the rush of air through their wings and even feel the breeze they generate.

You don’t want them to leave yet, because even your pushed film is too slow right now. Chances are they won’t, not if it’s still dark. They've spent the night on the water, seeking safety from the coyotes and Bald Eagles that prey on them, and they’re perpetually nervous about what might lurk in the shadows. The nearby cornfields provide much needed food, but in the darkness the land is far more threatening than the water, so they settle down again nearby.

It’s late fall moving towards winter, and you’re at Bosque del Apache National Wildlife Refuge for one of the greatest nature photography spectacles anywhere. Enormous flocks of photogenic Snow Geese, wings flashing black and white, and thousands of majestic Sandhill Cranes are drawn here each year to one of the few remaining wetlands along the vast Rio Grande flyway, where they can wait out the winter until spring and the urge to breed again sends them north again. Concentrated in this small area, they provide abundant subjects for the bird photographers who migrate here as well.