Some scientists believe a 6th mass extinction is underway. We hear from New Yorker writer Elizabeth Kolbert who's the author of "The Sixth Extinction: An Unnatural History." We also found a high school class in Jefferson County that's reading the book. Then, a state tax you didn't know you had to pay: The U.S. Supreme Court let stand a Colorado law that requires online retailers like Amazon to tell customers how much they owe in state sales tax. Plus, Colorado bands that had a good year and are poised to break out in 2017.