Beer companies are asking a judge to dismiss a $500 million lawsuit by an American Indian tribe that accuses them of knowingly contributing to alcohol-related problems on an impoverished South Dakota reservation.

Attorneys for the brewers, retailers and distributors filed motions Friday to dismiss the lawsuit.

The lawsuit was filed in February by the Oglala Sioux Tribe, which governs the Pine Ridge Indian Reservation.

The tribe alleges four beer stores in the tiny Nebraska border town of Whiteclay sold to its members, knowing they would take it back to the dry reservation.

Attorneys for the beer companies say the businesses all operate lawfully outside of the reservation's borders.

Whiteclay has a population of 11 people and sold the equivalent of 4.3 million, 12-ounce cans of beer last year.