Michael de Yoanna

As officials chalked up dozens of "mystery drone" sightings to things like reflections on jets at Denver's airport, residents in Colorado and bordering states continue to post grainy videos that they insist are evidence of large drones flying in groups. Meanwhile, a legal expert is voicing concerns about privacy.

Safety advocates worried about injuries at Colorado's ski resorts say months of talks with the state and industry about the hazards of riding chairlifts and other issues went nowhere. One group, concerned about children who fell out of lifts, says the state's Ski Lift Safety Working Group lacked focus and a mandate.

Kelli Jantz lost her son, Jake Snakenberg, during a high school football game. She will never forget his last moments on the field.

"He lined up," Jantz said. "He set. And then he fell forward and was trying to get up and you could tell something wasn't quite right. He turned to come to the sideline and he went down and that was it."

He never got up again.

When Erin Morris went to a show-and-tell to talk about her service in the Army, she was surprised by what the kids wanted to know. They weren't interested in guns or tanks.

"They wanted to know, 'What did you do every day? Where did you eat? Where did you sleep?'" Morris said.

An array of radio towers sits behind security fences amid farms and pastures north of Fort Collins. This is home to WWV, the country's oldest radio call letters. The station's high-frequency broadcasts can be heard around the globe if you have the right kind of radio.

Now playing: pulsing sounds, every second, followed by an announcement of the exact time.

The station is run by the National Institute of Standards and Technology in Boulder, which is home to the atomic clock. WWV is capable of more than telling time. It could, if need be, save the world.

When the flood waters in 2013 subsided, tens of thousands of evacuees along Colorado's Front Range returned to see what happened to their homes. One of them was Amanda Anderson.

"All of it was just mud," Anderson said. "It was so dark in there because of the mud. It was like walking into a horror movie because it used to be so bright."

During World War II, the U.S. military assembled a special group of troops trained to use chemical weapons.

"The big day is still to come," says the narrator of a U.S. War Department training film. "It will be when Hitler, with his back to the wall, frantically uses gas as a last resort."

It was the worst kind of warfare imaginable in the years before the atomic bomb.

The Pueblo Chemical Depot is one of the top 10 U.S. Army domestic installations "at risk" because of climate change. That's according to the Army, which lists "desertification" as its concern for the depot where tens of thousands of chemical weapons are in the process of being destroyed under international treaty.

A crowd gathers under a red and white striped tent. An emcee introduces Ryan Lanham, a veteran of the war in Afghanistan who lives in Fort Collins.

He’s working on a memoir about the horrors he faced as an Army infantryman intertwined with his years of alcohol and drug abuse. His vignettes are “snapshots of existence,” the emcee says, “that form a gestalt mosaic of a life upended, a turning away from the light, his dark night of the soul.”