If you find yourself in the North Conway area looking for bouldering the closest place is Humphrey’s ledge. On a hot summer day it’s perfectly located right near the Saco River, in the autumn the trees turn a brilliant shade of yellow, and in the spring a bit of a breeze keeps the black flies down to a reasonable level. Most of the problems are medium to difficult, short and sweet.

Autumn bouldering in New Hampshire
The approach to the boulders is about 1.75 minutes, if you’re slow. Located about a miles or so north of Cathedral Ledge on Westside Road, the boulders a sprinkled along the roadside at the bottom of the cliff, but not visible from the road, which helps to keep the rif-raf out.

Other spots to check out if your searching out some bouldering; Pawtuckaway State Park, Rumney, Bartlett and just over the border in Fryeburg, Maine is Jockey’s Cap. You can find some more details on the bouldering at New England Bouldering.
You can always get more info at the local rock climbing shops, or talk to some of the guides from the area.