Easiest way to be sure is to read the size of the tire. I'm pretty sure it's an F series mountain bike, built specifically for Backroads for use by people on their bike tours. The long serial number on the fork(?) appears to be specific to Backroads. Head tube decal would help place the year, as would a CAAD number if it has one. Approximately late 1990s vintage. Looks to be in great shape, especially for a rental bike.