We r planning a trip for late October in berkshires (staying in Lenox) . We r 2 couples looking for outdoor activities. Any suggestions.

You will have passed peak leaf season but there may still be some leaves on the trees. The Bershires have many beautiful walks and hikes, it may be quite chilly( we have been known to have snow in October but usually not).

Google "Trustees of Reservations." Most of their buildings will be closed for the season, but their properties have fine walks and hikes. There are Massachusetts, Connecticut, and New York parks and reservations, and the Appalachian Trail crosses the corner of Connecticut and Massachusetts.

Hike up Mt Greylock

Mt Greylock is a good recommendation - keep in mind that it's elevation is ~3500ft so you'll need to plan accordingly for the trail and time.

You can also drive your car up to the top of Mount Greylock.

A great shorter hike is to the top of Monument Mountain - very easy to get to with the parking area right on Route 7 just north of Great Barrington. It's elevation is only ~1600ft, so this could be an easier and shorter hike than Mt Greylock; you only need about 2 to 2 1/2 hours round trip. There are 2 paths up to the top - a longer, more gradual trail, and a shorter steeper trail (Hickey Trail). The Squaw Peak trail connects them so you can do a loop, i.e., we like up the gradual trail and down the steeper trail. There's some great views from the top, esp Devil's Pulpit lookout.

Yes, the summit of Mt Greylock is ~3500'. And the trail head is about 1200' elevation, so the elevation gain is ~2300'. It makes for a good most-of-the-day hike if you are in shape.