A Montana man has been charged with felony assault after attacking a 13-year-old boy who he said refused to remove his cap for the national anthem at a county rodeo, the authorities said. The confrontation left the teenager bleeding from his ears and with a skull fracture, according to prosecutors.

The man, Curt James Brockway, 39, of Superior, Mont., grabbed the youth “by his throat, lifted him into the air, and slammed the boy into the ground,” according to an affidavit filed by the Mineral County attorney’s office.

Mr. Brockway told a sheriff’s deputy that the boy “was wearing a hat as the anthem began, and Mr. Brockway asked the youth to remove his hat because it was disrespectful to wear one’s hat during the national anthem,” the affidavit said.

Mr. Brockway also told the deputy that the boy had responded with an expletive, according to the affidavit.