Located in Somerset County, off of Rt 27, hike info at:http://www.njhiking.com/nj-hikes-six-mile-run-reservoir.php
It was supposed to be bitter cold so we wanted to do a short hike, nearby. We hadn't been to Six Mile Run in quite awhile, after doing the short BLUE there trail years ago and didn't think that much of it, as it skirted a lot of fields and such.
I just read that JORBA (jersey off road biking association) had been developing trails there, and found a new map on their site that listed more trails so we gave it a shot. It turned out to be a nice sunny day and we ended up doing 11.7 miles, all of the park but the Blue trail. If you go, skip the orange trail... it's loops and twists upon itself thru a dense pine forest... which has to be lots of fun on a bike but rather tedious for hiking. We expected as much from looking at the map, but wanted to check it out regardless.
JORBA did a nice job creating the trails, and the park is prettier and more varied than I expected (forested, fields, a stream and some dense pine). The signage is good, although there are a few places where it's missing and left up to you to guess.
One caveat... all the trails are multi-use and even on a 30 degree day there we saw several mountain bikers and no other hikers. The trails are built with bikes in mind and are very twisty... many times bikes came up on us and we never heard them. If there were this many bikers when it was this cold, I imagine a summer day would be packed.
Everyone was exceptionally friendly and pleasant, but hiking on biking trails can get a little annoying... and I assume it's annoying for the bikers to run into hikers too.