Route: Castle Trail/Israel Ridge Trail Loop, Mt. Jefferson, Randolph NH

Percentage Runnable: 25-30%

Distance: just under 10 miles 

Elevation: change: 4,400'

Parking: Castle Trailhead, 1095 Presidential Hwy, Randolph, NH 03593, 93 miles, 1:53 from Lebanon

If you've been reading my column for a few months, you've probably noticed that I think the best trail runs involve some hiking. Or, maybe the best hikes involve some trail running. 

This loop over Mt Jefferson is the latter. If I may add that the best hikes/runs involve some rock scrambles, this one has it all! 

I read about the Castellated Ridge, which Mt Jefferson flings out to the northwest, in the White Mountain guidebook. I had hiked Jefferson via the Caps Ridge Trail several times; it's known for starting at the highest trailhead of any White Mountain 4000-footer, and therefore is a quicker way to bag an over-5000-foot peak than many routes. Now in search of more interesting ways to go up, I read about the Castle Trail, which is described in the Guide as providing "magnificent views in a spectacular setting," and "rough, with some difficult rock scrambles."

The first and last 1.5 or so miles of the route are comfortably runnable, and the rest of the loop involves rock scrambles and steep climbing up Jefferson, then a steep descent into Edmands Col before taking the more gradual and often runnable Israel Ridge Trail back down to the junction with the Castle Trail. 

The key to me is not to become a statistic. I would only recommend doing this route as a runner (which means moving fast and light) on a day that is sure to be pleasant - zero chance of rain and temps such that I can pack light. On a colder day, I would wear tights and pack a windbreaker, but I would not go on a day when I needed more than that, and certainly not when there's any chance of snow or ice. My trip was in mid-September. At other times of year, I would pack much more gear and make it a hike.