On July 20, a mass shooting occurred inside a Century Movie Theater in Aurora during a special midnight screening of the film The Dark Knight Rises. It was one of the worst mass shootings in U.S. history.
A gunman shot into the audience with multiple firearms, killing 12 people and injuring 58 others.
Police arrested a suspect a short time after the shooting outside the theater.
The High Park Fire broke out in Larimer County in June, becoming the second-largest wildfire in Colorado history.
The fire burned 87,250 acres.
It killed one person and destroyed 259 homes.
The Waldo Canyon Fire forced the evacuation of 32,000 people in and near Colorado Springs in June. The 18,000-acre fire burned 347 homes to the ground. Two people died when their home burned down.
This is just one section of a Colorado Springs neighborhood devastated by the fire.
The Lower North Fork Fire, triggered during a prescribed burn by the Colorado Forest Service, burned 27 homes near Conifer in March.
Two people died in the fire that swept through a Jefferson County mountain neighborhood.
In October, a 10-year-old Westminster girl named Jessica Ridgeway disappeared on her way to school.
Westminster police released this photo of the command center where the investigation into Jessica Ridgeway's death was directed.
Hurricane Sandy savaged the East Coast in October. At least 253 people were killed along the path of the storm in seven countries.
The storm became the largest Atlantic hurricane on record, with winds spanning 1,100 miles Preliminary estimates of losses due to damage and business interruption were estimated at $65.6 billion
In December, twenty children and six adult staff members were shot to death at Sandy Hook Elementary School in Newtown, Connecticut. The shooting renewed the gun control debate.
Denver took center stage for the second presidential debate between President Obama and challenger Mitt Romney. The debate was held at the University of Denver.
President Barack Obama was relected to another four-year term in early November.
Also in November, Amendment 64 was passed by Colorado voters, making it legal to posess small amounts of marijuana. Colorado and Washingtron state are the only two states where the pro-pot measure passed.
CU student Andy Duann captured this photo of a tranquilized bear falling out of a tree. "Falling bear" quickly became an Internet meme until it was revealed the same bear was struck and killed a few weeks later.