Undoubtedly among the most famous climbs on the east coast, the Whitney-Gilman is an early route up Cannon Mountain. It's between four and six pitches, never harder than 5.7 or 5.8, and certainly feels more alpine than most routes I've been up in New England.
Unfortunately, the guidebook for it is out of print. I wrote up a short description for a friend, which I've included here.
Having said that, it's a hell of a route. Ask if you have any questions, tell me if you have any improvements.
Here, more or less, is how to do the Whitney-Gilman. At least, this worked for us. This time I went with pretty short pitches, since I was getting cold and scared. I'll indicate which ones can be combined...
To get there, drive up the highway through the middle of New Hampshire -- 93, maybe? -- past the Kancamagus Highway and up a little. There are two exits to see the Old Man of the Mountains. Take the second one and turn around so you're heading south again, possibly you're on the highway again... parking lot on right; park there. You'll know you're in the right spot if, at the southwest corner of the lot, there's a sign-in book for climbers.
Follow the paved (!) trail south for a few minutes. Look for a climbers' trail, marked with a cairn, on the right. Find it, follow it up. I'm assuming you have a photo of the WG, so you'll know what to look for, roughly. Basically, it's a ridge on the southern end of the cliff, just before the cliff becomes broccoli. Scramble up the talus until you're at the base. The approach probably takes somewhere between 45 minutes and twice that.
Scramble up a bit until you're at the base of an offwidth. May as well rope up here.
P1: Follow the offwidth (or avoid it, like me) and work your way up until you're at a big, comfy belay ledge below a crack with a pin.
P2: Clip the pin but _don't_ climb the crack it's in. Rather, move to the right a few feet and follow an easier crack up. (Or do the first, I don't care... Steve tells me the crack with the pin is on the order of 5.hard, as opposed to the right-hand crack which is 5.easy.) Work your way up maybe 10-15', and then it gets just a little exposed. You'll see a grave for pink tricams a few feet away across a slight void. Move left, back where the first crack would have dumped you out, and keep going up.
The original pitch two ends at another big platform; you can build an anchor by stuffing things in at your feet. The third pitch then swings left, following old metal through loose rock until you come to an alcove.
But, they don't want us to climb that any more. So, instead, follow a few slabby feet past a good nut placement to a 5.8 crack maybe 20' high. Climb it; belay.
(That crack's the one I fell out of. I have a list of excuses as long as your arm, but the simple fact is that I fell.)
P3 The pipe pitch! Make your way up and right on increasingly steep rock. I found this bit a little awkward, but the holds are always there and almost always huge. Continue up through overhanging rock, past the (replica) pipe, clipping fixed gear if you're chicken like me. Exit left and up to a nice, big ledge.
P4 The climbing starts off a litle tricky -- maybe off to the right? -- and then you head up very easy ground. I wound up belaying on a platform off to the left, at the base of a short crack trending slightly to the right.
P5 This one's fun. Make your way up the crack and continue up and right. At one point, you wind up laybacking the actual Whitney-Gilman ridge! Then come back left a bit and follow the fixed gear (including an absolutely mauled 0.5 camalot) up some steeper rock. Run off into the trees; you're done!
Pitch notes: P3 and P4 can be combined, if you can handle the rope drag. P2's a little long and can be broken up, if you're running out of gear or bored or (my case) taking a breather from a fall.
Gear: Embarassingly, I placed next to no nuts. Used a ton of tricams, but I know you won't. I dragged a number 3 camalot up, but I don't think I ever placed it except as part of an anchor. Never went smaller than yellow alien/pink tricam. I meant to bring up a bunch of hexes but accidentally left them in the car. I think they might have been useful. Bring a bunch of draws if you want to clip all the fixed stuff.
Descent: Follow a trail up and left. Eventually it heads down a gully, and winds up back on the paved trail.
As if you can't tell, I've never written a route description before. Please ask if there's anything you'd like me to clarify.
See you, somewhere.