While there are many Canadian geese, or more properly Canada geese or Branta canadensis, that stay in Colorado year-round, the majority migrate through the from as far north as Alaska and Canada in route south to Texas, southern California, and even northern Mexico for the winter.
How many come through Colorado? Hundreds of thousands. And while most migrate, many have decided to become Colorado geese, posing an urban-wildlife problem for many muncipalitites.
Over the past several years, Denver has worked to cull the population of geese who winter over in the mile high city. Geese are captured, killed, and then given to hungry families, and in the spring oil is sprayed on eggs in nests to prevent them from hatching.
Hunters also help to reduce the population. Waterfowl hunters who are 16 or older need a small-game hunting license and a $33 Federal Migratory Bird Hunting and Conservation Stamp (Duck Stamp) and the $12.15 Colorado State Waterfowl Stamp.