CBS Denver

Xcel Energy's SmartGridCity is supposed to be an experiment in what a modern energy grid might look like.

A frog that hasn't been seen at Great Sand Dunes National Park and Preserve in more than 40 years has returned.

Homebuyers who would like to get a feel for a neighborhood before buying a home might want to hop on a bicycle. Matt Kolb, president and founder of Pedal to Properties, says cycling around a potential neighborhood gives potential buyers a better understanding of the neighborhood and saves the environment as well.

Most tires are made mostly from petroleum, but now a Japanese tire maker is turning to a renewable substance that's totally natural.

Wesley Clark, James Cameron and T. Boone Pickens -- those were just a few of the names of Hollywood stars and Washington politicos who were in Aspen over the weekend to talk about the future of green energy in the U.S.

The National Trust for Historic Preservation says it plans to acquire a historic school in central Denver and turn it into a national model for showing how older buildings can meet high standards for energy efficiency and sustainable development.

A federal appeals court Tuesday decided that mud washing off logging roads is pollution and ordered the Environmental Protection Agency to write regulations to reduce the amount that reaches salmon streams.

The Fort Collins Bike Library is working to reduce air pollution from cars. So far nearly 5,000 members have borrowed bikes to tool round town, and that number is growing.

The impact of the oil spill in the Gulf Coast could be felt for years, if not decades, to come.

Interior Secretary Ken Salazar struck a conciliatory tone Tuesday in Utah, saying it was possible to resolve decades of conflict over development and preservation on the two-thirds of the state's land that is owned by the federal government. Much of it is spectacular canyonlands and raw wilderness.

Transportation Secretary Ray LaHood took a bicycle ride in downtown Denver with Mayor John Hickenlooper to promote a bike-sharing program the secretary called "a model for America."

Denver Water wants approval to take even more water from the Fraser River and pipe it to Denver as part of its Moffat Firming Project.

Thousands of volunteer hours have gone into creating a new community in Colorado. They're new energy-efficient homes built by Habitat for Humanity.

Gov. Bill Ritter is challenging Colorado businesses to reduce energy consumption. The governor plans to reward 13 companies Thursday for taking part in the Colorado Industrial Energy Challenge.

Sam Tallent has started a green revolution in the town of Lyons. Four years ago, Tallent, the owner of the Stone Cup Cafe, bought an electric golf cart to get around town. Now after a town ordinance passed, golf carts are street legal.

There's a new push to reduce congestion on Highway 36 and the Boulder Diagonal. The goal of the 36 Commuter Cash Program is to get solo drivers to change their commuting habits and the incentive is money.

Natural gas industry groups on Tuesday urged the Environmental Protection Agency to limit the scope of an upcoming study on the effects of a natural gas extraction process known as fracking.

Some Coloradans might have noticed an increase on their last Xcel Energy bill. The company's new two-tiered billing system has kicked in, but there are ways to save.

A conservation group says it's concerned about vandalism, looting and destruction at the Canyons of the Ancients National Monument in southwest Colorado and other protected lands.

A developer proposing a biomass facility in Vail is reviewing its funding options after losing out on more than $20 million in federal grants June 30.