CHEYENNE, Wyo. (AP) — A federal judge in Washington DC has ruled against environmental groups that challenged the U.S. Interior Department's plan to open the Fortification Creek area in northeastern Wyoming to coal-bed methane development.

Judge Barbara J. Rothstein last month ruled against the National Wildlife Federation, the Powder River Basin Resource Council and the Wyoming Outdoor Council.

The groups had claimed that the U.S. Bureau of Land Management improperly analyzed how opening the area to development would affect the local elk herd.

Shannon Anderson with the Powder River Basin Resource Council says groups haven't decided whether to appeal.

Wyoming supported the federal government's position

Renny MacKay is spokesman for Wyoming Gov. Matt Mead. MacKay says the BLM plan balances protection of elk and elk habitat while facilitating natural gas production benefiting the state.