That is the Heritage Trail which is actually a snowmobile trail. The current snowmobile route takes the Gale River Loop Road passing the trailheads because a bridge on the HT is out. The HT is skiable to the west up to the missing bridge and to the east for a distance (it eventually connects to Gale River Loop Rd). There are bridges ~100 yds on either side of the junction which allow hikers/skiers on the Garfield Tr to bushwack around the two stream crossings. See http://www.vftt.org/forums/showthread.php?t=11956 for more detail.
Beaver Brook is a summer picnic/winter XC ski area. Some hikers have taken to snowshoeing the ski trails to access the Garfield Ridge and/or Gale River Trs. (It doesn't really save much over walking the roads and was primarily useful when the bridges on the Gale River Loop Rd accessing the Garfield Trail were out.) See http://www.fs.fed.us/r9/forests/white_mountain/recreation/winter_activities/skiing/BeaverBrook.php for more info on the ski trails.
