GREEN RIVER - Federal officials are beginning environmental studies for a pair of proposed pipeline projects that would move the state's natural gas from south-central Wyoming northeast through the Powder River Basin to Upper Midwest markets.

TransCanada Pipeline USA recently filed a Federal Energy Regulatory Commission permit application for the proposed Pathfinder Pipeline Project and for Northern Border Pipeline Co.'s Bison Pipeline Project.

A TransCanada subsidiary acquired Bison Pipeline LCC from Northern Border last month.

The proposed pipelines aim to keep pace with drilling in the Rockies, where natural gas production is pushing against available pipeline export capacity, keeping the price of the region's natural gas well below the national average in recent years.

The agency is beginning work on an environmental impact statement for the proposed projects, FERC officials said in a notice this week.

The proposed Pathfinder project is an approximately 673-mile, 36-inch and 42-inch diameter interstate pipeline that would transport natural gas northeast from Meeker, Colo., through Montana to the Northern Border pipeline system in North Dakota.

Gas would be delivered through the pipeline into the Ventura, Calif., and Chicago-area markets, according to plans.

The project would consist of four segments: the construction of 130 miles of pipeline from an existing hub near Meeker, Colo., to Wamsutter, followed by 236 miles of pipeline from Wamsutter to Dead Horse in Campbell County, 297 miles of pipeline from Dead Horse to Morton County, N.D., and 11 miles of lateral supply pipeline near Wamsutter.

Officials said the Pathfinder pipeline would have an initial capacity to move about 1.1 billion cubic feet per day of natural gas, with an ultimate capacity of about 1.6 billion cubic feet per day, the notice said.

The proposed 289-mile, 24-inch-diameter Bison pipeline system would extend from natural gas gathering facilities located in the Powder River Basin around Dead Horse and Fort Union.

The pipeline would also connect with the Northern Border pipeline system in North Dakota. The 1,249-mile Northern Border Pipeline transports natural gas from the Montana-Canada border to markets in the Midwest.

The initial capacity of the Bison pipeline project is estimated to be about 400 million cubic feet per day, with a maximum capacity of 600 million cubic feet per day.

FERC officials said the entire route of the Bison Pipeline is identical to that of the corresponding portion of the Pathfinder Pipeline.

The notice said TransCanada is proposing to build either Pathfinder or Bison, and once the company determines which of the two projects it will pursue, TransCanada will file a request with the FERC to discontinue review of the other project.

FERC officials said both projects have an estimated in-service date of late 2010.

Contact southwest Wyoming bureau reporter Jeff Gearino at (307) 875-5359 or gearino@tribcsp.com.

Last we knew: Gas pipeline companies have been examining various routes for new pipelines to help move natural gas out of the Rockies to markets in the Midwest.

The latest: Federal officials are beginning work on an environmental impact statement for the proposed Pathfinder and Bison pipeline projects.

What's next: The Federal Energy Regulatory Commission is accepting public comments on the proposals through Nov. 3. More information can be found at the agency's Web site (http://www.ferc.gov).