I've seen others refer to the Specialized Expedition as a mountain bike. It is a bit similar to one, as the geometry of a hybrid is similiar to a mountain bike. Especially if he has a 2006 or earlier model. Specialized changed the frame on their 2007 Expeditions and Crosstowns to a more relaxed hybrid. And it does have wider, 26" tires, which is closer to a mountain bike. And it has mountain bike gearing. So one could use it as a mountain bike-lite, on the easier trails. Specialized even promoted it that way. But the handlebar, stem, saddle, suspension and tire tread aren't going to be very MTB-like.