The Bolton exit on 495 is 6 exits north of the Mass Pike and 2 exits south of Rt 2.

From the North:
Take 495 South to Exit 27 (Rt 117).
Take a left (Rt 117 West) at the end of the ramp.
About 1 mile later take a left at the yellow flashing light.
About 1/4 mile later on the left will be a parking lot for the fields.
(If you get to Nashoba Winery, you've gone too far.)

From the South:
Take 495 North to Exit 27 (Rt 117)
Take a right (Rt 117 West) at the end of the ramp.
Go straight thru the light.
About 1 mile later take a left at the yellow flashing light.
About 1/4 mile later on the left will be a parking lot for the fields.
(If you get to Nashoba Winery, you've gone too far.)