WASHINGTON – The U.S. Senate on Friday unanimously passed bipartisan legislation designating the American bison as the national mammal.

"The bison, like the bald eagle, has for many years been a symbol of America for its strength, endurance and dignity, reflecting the pioneer spirit of our country," North Dakota Sen. John Hoeven said in a statement Friday.

Bison "remain intertwined in our state's heritage and traditions," said Sen. Heidi Heitkamp, D-N.D.

Sen. Martin Heinrich, D-N.M., joined Hoeven in sponsoring the bill and in championing its passage. He heralded the bison's importance to American Indians.

"Bison hold a rich historic and cultural significance for the United States, and in particular for our tribal nations," Heinrich said. "Recognition of our new national mammal will bring greater attention to the ongoing effort to conserve this unique species."

The senators pointed out that North America was once home to 40 million bison, but the population had dwindled to fewer than 1,000 by the late 1800s. "The species is acknowledged as the first American conservation success story," the senators said, with public and private bison herds now in all 50 states.

The Interior Department's seal features a bison, and three states — Wyoming, Kansas and Oklahoma — have already designated bison their state mammals, according to the Vote Bison campaign.

The coalition includes zoos, the outdoor clothing company Patagonia, the Howard University Alumni Association and the Minnesota Buffalo Association.

This isn't the Senate's first display of affection for the woolly creature. In 2014, the body unanimously designated Nov. 1 National Bison Day.