Van Horne spent 32 years of his broadcasting career with the Montreal Expos, 15 of those years partnered with former Dodger great Duke Snider. In 2000, as the Expos had not secured an English radio or television contract, Van Horne broadcast the season on the Internet.
With the Expos broadcast situation still unsettled for the 2001 season, Van Horne left at the end of 2000 to broadcast for the Florida Marlins. He projects much enthusiasm and excitement with signature calls of "Thanks Duke and Hi again, everybody. Glad to have you aboard for today's game..." at the start of every game and "up, up and away" for every home run. Van Horne broadcast the last Expos game in Montreal from the Marlins broadcast booth in 2004.