Every year I get out for a few longer dirt road rides and after I always feel like I should be doing them lots more often. They're quiet, scenic, often challenging rides that hark back to the roots of cycling. Southern New Hampshire is a great location in how varied the terrain can be within a reasonably short distance. A short way from the beach and ocean, a little further to the White Mountains, lots of scenic paved roads, many trails (which double as snow mobile trails in the winter) and of course, dirt roads not far from more populated areas, and even more the further you venture.
A trick to dirt road riding is getting the timing of the season right. Go during the summer and you're likely to get swarmed by deer flies, go earlier in the spring and things can be pretty muddy. Cooler weather in the fall makes for some great riding and less bugs, and winter riding is a hidden gem if there isn't snow cover. In the winter the dirt is hard packed and the more narrow wooded roads offer more shelter from the wind.
A fun aspect of dirt roads, especially Class VI unmaintained roads, are the landmarks you'll find - from long abandoned cars (and even school buses!), to derelict shacks and long forgotten cemeteries - there's history to contemplate as you pedal and wonder how some of those things came to rest where they are, or who once lived that is now in the overgrown cemetery that no one seems to visit anymore.
An event called Raid Rockingham passes within a mile or two of my house and it's course includes several good local dirt roads. I've ridden the 2012 course once a year for the past 3 years when I'm craving dirt roads and am not feeling very creative with my route, it's a solid fallback. There's one drawback to doing this route yearly however - every year I ride it some dirt road, often one of my favorites, gets paved or partially paved. In 2013 they paved the top half of the longest dirt climb of the course, one not far from my house that was an ideal early season training climb for the Tour of the Battenkill. In 2014 two more have been partly paved, including one that was admittedly a somewhat sketchy windy downhill, but that's part of the fun.
It's one of the downsides of living somewhat close to civilization - things keep getting more and more developed. What was an ideal balance of convenience and back country 5 years ago is more and more developed now, and in another 5 years time who knows how much of that back country aspect will be left. We're left to move every few years to maintain the same balance, or get really lucky in the location we pick and be able to hold out a little longer. Dirt roads are just one of the pieces of New Hampshire that help it maintain the draw it has to nature lovers all around New England, and they're slowly but surely disappearing. Is there much we can do about it? We can lobby our towns and vote against propositions for funding to pave dirt roads, but ultimately, probably not. We just need to get out there and enjoy them while we can.