Each spring, hundreds of thousands of swans, geese, cranes and other waterfowl descend on a Montana lake on their way to the Arctic. A small town festival draws thousands of bird fans.

The sky above the town of Choteau, Montana ... of birds fills the air. (SOUNDBITE OF BIRDS SQUAWKING) JUHLIN: Lisa Hudnutt, a retired local teacher, quickly sets up a spotting scope. Colors ...

Each spring, the sky comes alive along Montana’s Rocky Mountain Front. Huge flocks of migrating geese, swans and other birds ...

Huge flocks of migrating geese, swans and other birds swoop into the lake for a rest on their long migration from as far ...

The standout attribute of spring is that it heralds the return of heavy coats to the closet. Not put away, mind you. There’s still a healthy snow squall or two before us. But the worst of winter ...

Invasive trees are a threat to rangelands. Early detection is key to rapid response in managing them. The tamarisk tree is ...

Delicate trilliums, glorious columbines, and flamboyant redbuds are some of the harbingers of spring found across the ...