Black Spruce Bog hike: like a trip back to prehistory

CORNWALL — Hiking always demands some preparation:the right footwear, water, a map. A flashlight. But one face of Mohawk Mountain has a section so unusual that it calls for preparations that are different, even unique. It is an easy, mostly flat hike on a loop no more than a mile long. The only essential is that hikers do a little homework beforehand. The Black Spruce Bog can only truly be appreciated when one knows its back story — which would be 10,000 years of history.What makes it most remarkable is what cannot be seen. Beneath a carpet of lime green sphagnum moss, and a tree canopy of black spruce and tamarack (American larch), is a crater filled with more than 40 feet of partially decayed plants. Doesn’t sound very attractive, but it is the only last-stage peat bog in Connecticut. It is part of the Mohawk Mountain State Forest and the state’s Natural Area Preserves System.Expecting its location to be shrouded in mystery leads to disappointment. The state park is accessible from two roads off Route 4. From Toumey Road, where a parking area and signage mark the main entrance, turn left on Mohawk Mountain Road. Or take Allyn Road, which turns into Mohawk Mountain Road as it enters the forest. In front of maintenance buildings on one side of the road is parking and a kiosk that offers essential bog information. The trailhead is directly across the road.The hike begins with about a tenth-mile trek that slopes gently downhill. At the beginning of the bog, a sign advises hikers they are in an “Environmentally sensitive area. Please remain on trail.”The trail is a double-plank walk that meanders through the bog and then loops back on itself. The walkway is there to protect the sensitive ecostructure. It makes for a great hike, however, if one is more in the mood to survey the surroundings and admire the tree canopy than to concentrate on the trail and one’s footing.The bog is regularly described as something from another era, and it truly is. But one has to make an effort to connect to the history of the place.On a recent hot July day, after several days without rain, the boardwalk at first appears unnecessary. But careful observation reveals boggy areas and what may be a small streambed. The trek would not likely end with clean shoes. Here and there, where the mossy carpet is not concealed by brush, cinnamon fern, wild calla, pitcher plant and sundew, mushrooms sprout. These are all signs of wetlands.So what happened here 10 millennia ago?Picture a barren landscape, a frozen tundra near the end of the ice age. Runoff from a melting glacier filled — and was then trapped in — a bedrock depression. Over time, simple vegetation began to grow, covering the pond. From that layer, decaying plant material rained into the pond. Deprived of oxygen, the material formed a growing layer of material semipreserved in its semi-decayed state: peat moss. Eventually, woody plants or shrubs, possibly the sheep laurel and highbush blueberry there now, could be sustained. The bog continued to progress without really changing. Today, it is dense with towering blue-black spruce punctuating a lime green tamarack canopy. It does feel out of time to a degree, as one follows the boardwalk, which is dappled with sunlight and is overgrown in spots. In two spots, platforms with benches extend off the walkway, detracting from the aura of antiquity. Planes drone overhead, reminding one that civilization is nearby. Deep into the bog, while lingering at the top of the loop, a sound comes that seems to be a piece of landscaping equipment in the distance. The noise comes closer, and it turns out to be a very large, prehistoric-looking insect. Right on cue, as if to say, “This is not like any place you have ever been.”