Article Photos: State-by-state look at frigid blast hitting US 8/36

Cheetahs Mojo and Marvin, who are brothers, pass time inside their pen, at Denver Zoo, which was closed to the public due to extreme cold, in Denver Thursday Dec. 5, 2013. A wintry storm pushing through the western half of the country has brought bitterly cold temperatures that prompted safety warnings for residents in the Rockies and threatened crops as far south as California. (AP Photo/Brennan Linsley)