A battle over federal approval for a Texas oil pipeline has been as twisted as a Lone Star cyclone.

The Navajo Refining Co., previously fined almost $2 million for its environmental transgressions, has teamed with greens to spout the virtues of federal environmental laws to sue a competitor, Longhorn Partners Pipeline. Via a pipeline not used since the early 1990s, Longhorn hopes to transport gasoline into a market served by Navajo.