In the years to come, the air over Rocky Mountain National Park in Colorado is expected to be cleaner thanks to a negotiated settlement that will reduce emissions from power plants in the western half of the state,

Under the settlement reached between the National Parks Conservation Association, Tri-State Generation and Transmission Association and the owners of the Yampa Project at Craig Station, the state of Colorado, the Environmental Protection Agency, and Wild Earth Guardians, there will be reductions in nitrogen oxide emissions produced by coal-fired units in Craig and Nucla, Colorado. These emissions contribute to haze pollution in the region, impacting the air quality at a dozen iconic “Class I” national parks and wilderness areas in Colorado and Utah, according to an NPCA release.

There are 156 designated Class I areas required under the Clean Air Act to have the most pristine air quality in the country. As a result of the agreement announced last week, there will be less atmospheric pollution, and places including Rocky Mountain, Canyonlands, Arches and landscapes across the Southwest will realize cleaner air, as will their visitors and neighboring communities.

National Park Service Director Jonathan Jarvis calls climate change the biggest challenge facing national parks in their second century. By closing Nucla Station and Craig Station Unit 1 coal-fired power plant units, there will be reductions in greenhouse gas emissions as well as health-harming, haze-causing pollution, the NPCA release said.

Emissions of nitrogen oxides for example, contribute to high ozone. This harms public health and adds to visibility-impairing smog. In addition, research has shown that nitrogen oxides from the air are deposited in park soil and water, affecting animal and plant life. The agreement is expected to improve Rocky Mountain National Park’s sensitive alpine ecosystems, water quality, and the visitor experience at parks across the Southwest, NPCA said.

Under the agreement, Tri-State will (1) cap emissions at both Craig and Nucla plants by 2020, (2) retire Craig unit 1 by December 2025 or transition the unit to gas by 2023, and (3) retire the Nucla plant by December 2022. The coal plant closures will result in important reductions of carbon dioxide emissions and will help Colorado meet the objectives of its recently announced Colorado Climate Plan.

“National parks are located in some of the places that are most vulnerable to climate change and pollution, from the deserts of the Southwest to the glaciers of the Northern Rockies. We must therefore do all we can to ensure clean air and a healthy climate for parks, wildlife and the more than 300 million people that visit these treasured places each year," said Stephanie Kodish, senior director and counsel for NPCA’s Clean Air Program. "Under this historic agreement up to 4.7-million metric tons of carbon dioxide, a greenhouse gas, will be eliminated by 2025. This is like removing 1 million cars from the road each year. The closure of Tri-State’s coal plants will mean fewer emissions contributing to climate change and healthier, clearer air for people and national parks including Rocky Mountain."