Which way do the snow geese go?

Today it is snowing and it puts me in mind of the snow geese. It occured to me that I have never seen or heard them in migration. Why not? Do they fly at night and in silence? Or so high they cannot be seen or heard? I started to ask around, but the answers are not readily available, at least among a few friends and on the internet. This seems odd considering that they are such a major wintering species here. At the peak of the season some 30-40,000 Light geese (including Blue and Ross' geese) are in the Middle Rio Grande Valley. Someone must have studied their routes.

I got in touch with Christopher Rustay and he shed some light, mentioning that he thought some must fly over the Manzanos to join the flocks flying up the Pecos and continuing up the front range. He sent me a map of the Sandhill crane migration routes made by NMDGF, and referred me to Joseph Sands at the

Department.