Some hybrids are fairly road biased and might be what you should consider. I'm not familiar with the Trek models that have been mentioned. I did just buy a Fuji Absolute 1.0 that is a little hard to differentiate from a road bike in many aspects. It has a flat handlebar, lots of fender/rack eyelets, and a gearing that is a little more biased towards trail use than a road bike would have so I guess it is a hybrid, as Fuji claims. Fuji isn't shy, they call it the ultimate hybrid! On the other hand it has the tasty entry level Shimano 105 road transmission and fairly skinny 28 mm tires and the frame does not look all that different when overlaid on some of Fuji's road bikes. Compared to the Dahon folder that I started bike/train commuting with last summer after many years of not cycling the Fuji is a rocket and all last summer I thought the Dahon was pretty quick when its Marathon Racers were pumped up to 85 psi! I don't know if 28 mm tires are wide enough for your packed dirt trails but you could probably use tires that are still narrow enough to work well on the road too on a road biased hybrid. Just to add a little more variety to the all Trek, all the time (just kidding) discussion here you might also consider the Marin Lombard. It even has drop handlebars, how much more roadie do you need to be?
Ken