I love driving from Missoula to Helena or Great Falls or Bozeman, over the big passes of the Continental Divide and along some of our country’s most spectacular rivers. On the west side of the Divide, we pass green foothills, huge ponderosas and larch, and soaring bald eagles and osprey. Dropping down onto the east side, we start to see grasslands, sage brush, mule deer and pronghorn. Travelers in Montana know that the climate on the east side of the Continental Divide is suddenly and