I was having a nice evening walk near one of the nature reservations in Andover MA, close to Tewksbury, when I've found such a footprint. I'm really sorry for image quality, though. So it's a wet, bog-like, piece of ground, two lanes of deep small holes (probably the actual footprints) - the distance between them is like 25-30 centimeters (10-12 inches) - and the ground in the middle looks like something was dragged. In the top left corner of a picture the ground seems to be pushed below, and the hole is filled with water.
I'm not from US, and have almost no idea about Massachusetts fauna, but to me it looks like a tortoise. It was lying on the ground, thinking it's slow thoughts - that's how the hole filled with water appeared - then it decided to do some action, got up and moved, dragging it's plastron upon the ground.
That's the best idea I have. But it should be pretty big tortoise, 10-12 inches wide. I wonder if there are any in MA. Does anyone recognize this footprint?