Yellowstone Air Quality Continuing To Improve - Houston Chronicle

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YELLOWSTONE NATIONAL PARK, Wyo. — The air quality at two of the most popular winter spots here continues to improve, a new study finds. Levels of carbon monoxide and certain particulate at the park's west entrance at West Yellowstone, the most popular winter gate, and Old Faithful, the most popular destination, still are "well below" national ambient air-quality standards and the air quality is good, the study by the National Park Service concluded.

Those pollutants have decreased in recent winters because fewer snowmobiles travel into the park and because of new requirements that all snowmobiles meet standards for noise and emissions, park officials said.

The study analyzes air quality at Old Faithful and the West Yellowstone entrance during the winter of 2005-06. It's the latest in a series of studies aimed at helping park officials decide how best to manage winter traffic in Yellowstone.

Late last year the Park Service released, for technical review, a draft plan to several counties and public agencies. A draft plan is expected to be released this spring for public comment, and a final decision is expected before next winter.

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