The Southern Utah Wilderness Alliance filed suit in U.S. District Court Friday to halt a proposed 2 million board feet timber sale in the Windmill area of Dixie National Forest.

According to the suit, Alliance members - who total 1,700 - use the forest for rec-reation, research and study. A timber sale contract for the Windmill tract on Boulder Mountain was scheduled to be awarded next week.An environmental assessment on the sale failed to adequately analyze potential im-pacts on water quality, watershed, sedimentation and visual quality, it charges. Also, it did not study sufficiently the cumulative and indirect effects of the timber cutting.

The Forest Service "has not demonstrated that the Windmill Timber Sale, a below-cost sale, will be in the public interest," it says. A below-cost sale is one that would cost the agency more money than the sale brings in.

The Forest Service claimed an administrative appeal of the sale by SUWA was not timely. "The dismissal of plaintiff's administrative appeal by the chief of the Forest Service was illegal and contrary to the clear duty . . . to hear such appeals," says the suit.