Radon is a hazardous gas, the second leading cause of lung cancer and something we take great pains to remove from our homes. So why do people travel from near and far to spend time in radon-filled mines in Montana?

In Montana, we're used to hitting the water in our tubes, rafts or waders and going wherever the river takes us. Anyone can recreate on streams in the state below the high-water mark — no matter who owns the land beneath them. This isn't possible in most of the country. How did we end up with such strong stream access protections, and what does the law's future look like?

The state constitution says the right of privacy is essential to the well being of a free society. Privacy affects issues from electronic data to abortion, and has come into play in decisions by the state Supreme Court. So why did Montana end up with such strong privacy protections and why does it matter today?

If you've ever seen or experienced a pickup pull alongside or in front of you and then belch out a huge cloud of black or gray exhaust — well, you've just been coal-rolled. But why?

Our question this week comes from a listener in Helena named Bob Flipovich, who wants to know who owns the most water rights in Montana. Water rights determine who can take water out of our lakes and streams, and how much they can take.

"I've heard so many different stories about how it got here and who's responsible, and I've never really heard the legitimate reason, and I thought that's a good question for you guys."

For this episode of The Big Why, we’re talking about salmon. They can travel hundreds of miles from the Pacific Ocean up the Columbia River to spawning grounds in Washington, Oregon and Idaho, but did they ever make it to Montana? That’s what fly fisherman and Anaconda resident Rob Murray wants to know.

For this episode, we're trying to answer a question with potentially cosmic implications: Flying saucers. Lights in the sky. Montana is a hotspot for UFO sightings. Today, Montana Public Radio reporter Edward O'Brien is tackling the question: Why are reports of UFOs so common in Montana?

Montana is home to more than 260 developed and natural geothermal sites. Huge resorts that once entertained the state’s wealthiest residents and off-the-beaten-path hot spots favored by locals. So we were curious: Where did Montana’s hot springs come from, and where are they going?

Welcome to The Big Why, a series driven by your curiosity about Montana. We'll answer your questions, large or small, about anything under the Big Sky. This is our inaugural episode and we're answering a question that has to do with this show's name: Why is Montana known as the "Big Sky state"?