Cycling vacation with the family - where should we go?

We're about to go on our first vacation in 2 years...maybe even 3 years, because DH and I have been so stinking busy. The kids (ages 9, 11 and 16), surprisingly, who are biking up to 20 miles per day (they can probably do more, we just have worked them up to that point).

We've been trying to think about whether we want to do a tour or a hub-and-spoke sort of idea and we've settled on the latter. For our first real vacation in so long, we're not ready to do the whole self-supported camping thing, and a planned custom tour is just too darned expensive. So we've settled on hub-and-spoke (meaning we'll rent a house or stay at a hotel in one location), and we want to be near a beach (fresh or saltwater perfectly okay), near enough to long enough trails that we can ride relatively easily (trekking the bikes over with the car is fine, but it would be even better if they were within riding distance), we want to be near other things to do....and we'd like to stay on the east coast - midwest - preferably the northeastern part, due to a proximal drive and taking a cranky teenager along.

Does anyone have any ideas for towns for us to look at? The kids are fairly capable on their bikes, but they have zero traffic experience whatsoever, and I'm not anxious to test those capabilities with the younger two (the oldest rides into town all the time...he's fine).

Thanks in advance!!

Vermont has some spectacular riding. We rode the Gaps a few years ago and did a couple of nice rides out of Middlebury. I don't know about a beach though - maybe Lake Champlain.

Acadia National Park in Maine is quite nice as well.

Veronica

I think Cape Cod has a bike trail system? (someone verify this, please)

Glenwood Springs,CO is a nice choice. The trails are relatively flat and the scenery is sensational.

There is really only one longer trail on the Cape and I wouldn't recommend it in the summer. A friend of mine who has a second home there just witnessed a kid getting crashed into by a witless rider who was speeding. Riding on the Cape in the summer kind of sucks. Really, any beach areas. You have drivers from out of town who don't know where they are going and riders who are really unsafe; no helmets, riding on sidewalks or against traffic, blatant disregard for traffic signals. And that's not counting riding in flip flops and carry a six pack of beer. Yes, I saw that on Block Island.
I second Arcadia National Park. Miles of carriage roads and also good road riding. Lots of other outdoorsy activities. We took a vacation there when our kids were12 and 14 and it was great.

I just came back from Maine. Took the Bike Friday's to Bar Harbor - Acadia National Park. There is a great loop one way road in the park. We rode around the 'quiet side of the island' - the part near Bar Harbor has too many cars, and we rode on the carriage trails. The carriage trails are 16'wide gravel roads made at the turn of the 19th century for rich people to ride carriages. There are 67 miles of road. I was concerned that the road surface would not be ok since I do not have a mountain bike, but it was fine. It's packed dirt with fine gravel and no ruts. It's like hiking on a bike to lakes and over stone bridges - lovely. So, we just went a little slower than on a paved road. The down side of that area is that lodging is quite expensive.

Katy Rail Trail is Missouri is a blast. Much of the trail is rural, but you can stay in St. Louis, Jeff City or Sedalia if you want to be in town. Check out bikekatytrail.com.

It's too hot here right now, but fall is peak season :D

Thanks for the suggestions, folks! I'll keep you posted when we pick something!