I'm sure you have ridden merli-sarnoski, but have you tried Prompton Dam? It's not as good as merli, but when it's dry, it's a great trail.
Also, Glen Park in stroudsburg is pretty good (although a far drive down Rt. 380). There are some pretty wild stunts hidden through out the woods, including a gap jump over a dirt road. It took some time to find our way around, even with a topo map. The LBS is very friendly and even invited us to park in their lot. (check the trail reviews for directions)
Seven-tubs in W-B is so-so, but there are very few spots where quads can't get to.
You will have a heluva time trying to find a trail in NEPA that does not have quad traffic. Although you are much less likely to run into one when a NASCAR race is on!!!

(no offense to NASCAR fans,

). Thankfully, they make enough noise to warn you ahead of time.
I'm in Kingston, but other than Merli & prompton I haven't ridden too much north of here. Where do you ride in Lackawanna county?