In the Autumn of 2001, on a routine inspection walk, we discovered flooding on the Rail-Trail just north of Union Street. Since the general weather pattern had been dry, this extra water needed further investigation. The abandoned beaver lodge on the edge of the trailway appeared to have been renovated! This was a sure clue. Beaver had returned and were the most likely cause of the water on the trail. We checked downstream and there it was, a beautiful little dam! The solution was to install a "Beaver Baffler". Four perforated pipes were set into the dam at a level that would prevent water on the trail but still keep it deep enough for the beaver. The beaver enter their lodge through an under water entrance. If the pond level is too low thick ice in the winter may trap them inside where they would starve. If the water gets REALLY low and the entrance is exposed then predators could enter the lodge and snatch the babies. It is easy to get a good view of the lodge, the dam and the baffler. If you are walking the trail from the parking area at DPW, you will see the lodge on your left just before Union Street about a half mile from the parking lot. The dam with its baffler is just downstream. Turn left and walk along Union Street toward Route 13. Just as you clear the guard rail turn left and walk about 20 feet. The beaver picked a great spot to build their dam. Abutments for an old road form a narrow place in Great Brook and hold the dam well. If you don't want to hike the half mile simply turn right onto Union Street from Route 13 and stop at the beginning of the second guard rail you come to. The dam is on your right. Look around and you will see lots of beaver activity in the area. To learn more about beaver and many other wildlife species check out eNature.com or the New Hampshire Fish & Game Fact Sheets.