Part of the Pawtuckaway State Park system of trails, the North Mountain Bypass trail is aptly named for its purpose.
Branching off just a little before halfway up the North Mountain Trail
, Bypass comes in right before the singletrack nastiness of the toughest part of the climb. If you're on North Mountain, your doubletrack will run into another doubletrack; everything is signed appropriately. If you head roughly straight across this doubletrack, you head up the brutal singletrack of North Mountain, and if you head right you hit this Bypass.
Bypass is comprised of doubletrack only, but there are some pretty steep sections that push the difficulty up a level. Nothing too techy to be had here, just some steep grinds that you'll just have to get after and muster some oomph! to conquer.
Around the middle of the trail, you'll come across the Chase Trail
, which if you follow down will take you to Reservation Road. If you continue on, you'll end up at another intersection where you can head right down an unnamed trail to hit Reservation Road at a different location, or keep left on the Bypass and end at Round Pond Road.