Hiking on an Ancient Volcano — The Ossipee Mountains

By Gordon DuBois

One hundred million years ago, the area of today's Ossipee Mountains was a very different place. What appear to be individual peaks are actually what is left of a large, now extinct volcano. It is thought that the volcano may have been as high as 10,000 feet, and would have looked something like Mt. Vesuvius or Mt. Fuji. Three major eruptions, each about 10 million years apart, changed the volcano into what is seen today. The second eruption, around 90 million years ago, created the famous ring dike.

Viewed from above, the Ossipee Mountain range appears as a nearly perfect circle, with the area in the center being relatively flat. The Ossipee Mountains that are seen today are really the subsurface remains of the old magma chamber that has become exposed over the years, and the flat area in the center is the bottom of the old caldera. The diameter of the range is 10 miles and the distance around the base is forty miles. The original volcano was thought to be around 10,000 feet tall, and the highest peak, Mt. Shaw, is today around 3,200 feet."

http://suite101.com/article/the-ossipee-mountain-ring-dike-complex-

After reading this excerpt from the web site noted above, I wanted to explore this familiar mountain range that lays east of Lake Winnipesaukee. I have hiked in this area many times, but had little knowledge of the geological significance the Ossipee Mountains. What particularly intrigued me the most was the columnar basalt formations found off the Bald Knob Cutoff Trail. These formations are not commonly seen. The most famous of these geological features are found in the Post Pile National Monument in California and Devil's Tower in Wyoming.

On a fine sunny day I set off with my dog Reuben in search of these geological formations. I knew that the Ossipees offer outstanding views of the "Big Lake" and westward to the Belknap Range as well as easy hiking on well-groomed carriage roads maintained by the Lakes Region Conservation Trust. The 5,381-acre Castle in the Clouds Conservation Area was acquired by the Lakes Region Conservation Trust in 2002 and encompasses over 28 miles of hiking trails stewarded by dedicated LRCT volunteers.

A trail map and guidebook can be purchased from the LRCT, We drove to Rt. 171, via Route 25 and 109. Just past the entrance to Castle in the Clouds we parked in the large parking lot on the right, across from the Shannon Brook Trail head. The trail starts as an easy grade climbing along the deep ravine of Shannon Brook. At 0.7 mi. the trail diverges to the right onto Bald Knob Cutoff which gets gradually steeper as it approaches Bald Knob. On this trail we found the basalt columnar formations, which are not nearly as impressive as the Post Pile National Monument or Devil's Tower but it's still a unique geological formation worth viewing.

After spending time climbing through these columns of basalt rock I continued my climb to Bald Knob where Reuben and I took in spectacular views of the "Big Lake" and beyond. Reuben seemed to be mesmerized by the vista and stood looking for several minutes into the distance contemplating his existence in such a wonderful world.

We then continued our journey to Turtleback Back Mountain via the Turtleback Mountain Trail. The mountain gets its name from the columnar formations that resemble a turtle shell. Here we enjoyed our lunch (Reuben his dog bones) and I found an abundance of fresh blueberries for dessert.

We also located cables that once anchored the 60-foot-tall observation tower.

After a long respite we decided to head down the mountain as storm clouds approached. We followed the Turtleback Mountain Trail, which is an old Carriage Road built during the late 1800s, when B.F. Shaw, a wealthy Boston industrialist, built this early resort site, now known as Castle in the Clouds. This was an easy walk of 3.7 miles to Shannon Pond. From here we picked up the Shannon Brook Trail, which would take us to the parking lot. However, we were diverted off this trail by our interest in the Brook Trail. As we descended into the Shannon Brook gorge we were rewarded by finding the impressive Falls of Song, a beautiful waterfall that should not be missed. A board walk has been constructed that will lead you to the base of the falls.

After spending some time sitting on a bench near the falls, watching Reuben swim in the stream, I decided to move on and return to the car as rain was approaching with darkening clouds overhead. Reuben and I hiked back up the Brook trail returning to the Shannon Brook Trail and eventually after a short walk we reached the car.

The approaching storm had interrupted my planned destination of reach the summit of Mt. Shaw and looking into the Caldera of the now extinct

volcano. However, knowing that this area is only a 45 minute drive from my home in New Hampton I can easily return for another adventure on this ancient volcano, known as the Ossipee Mountain Range.

Gordon has hiked extensively in Northern New England and the Adirondacks of New York state. In 2011 he completed the Appalachian Trail (2,285 miles). He has also hiked the Long Trail in VT, The International AT in Quebec, Canada, Cohos Trail in northern NH and the John Muir Trail in CA. Gordon has summited the New Hampshire Hundred Highest peaks, and the New England Hundred Highest, 98 of these in winter. He spends much of his time hiking locally and in the White Mountains with his dog Reuben and especially enjoys hiking in the Lakes Region due to the proximity to his home in New Hampton. He is also a trail maintainer for the BRATTS (Belknap Range Trail Tenders) and can be found often exploring the many hiking trails in the area.