DENVER (AP) -- The military command that protects the skies over the U.S. and Canada is also protecting the name of its famous Santa-tracking operation.

The North American Aerospace Defense Command has trademarked NORAD Tracks Santa and licensed a private company to sell official T-shirts and other gear.

NORAD began tracking Santa in 1955 when a newspaper ad listed the wrong phone number for kids to call Santa. They wound up calling the Continental Air Defense Command, NORAD's predecessor.

Last year, NORAD Tracks Santa answered 102,000 phone calls on Christmas Eve. Its website attracted 18.9 million unique visitors from 220 countries and territories in a December alone.