Hike to the Tufa Mounds
We were out of the tents early today and on our way across the river to the Warden's cabin. Ann, the warden we had met the day before, was going to lead us on a tour of the tufa mounds. This was an interpretive hike about the area, which is renown for its volcanic activity that has resulted in what was once romoured to be a tropical paradise. Geothermic activity has given rise to hot springs, emerald green lakes, and tufa mounds.
Tufa mounds are created when minerals are dissolved to the point of super saturation in hot springs that originate deep within the earth. As the water reaches the surface it begins to cool and the minerals, predominantly calcium carbonate, begin to precipitate out of solution and form a large structure resembling a mound of sandy coloured concrete. Indeed, calcium carbonate is one of the ingredients of cement, which is in turn one of the main ingredients in concrete. The tufa mounds in the Nahanni region are believed to be 10,000 years old and because of the fragility require us to walk on them in our bare feet.
On the hike in the morning were the five people in our group, plus Brian and Bert, two guys who had been camping on Rabbitkettle lake. They were the early risers in a group of six people who were headed to Virginia Falls in two days time.
The round trip to the tufa mounds took us about four hours and involved hiking three and one half kilometres one way. We needed to cross the Rabittkettle river and this was accomplished by a scow-ferry attached to a cable and pulley system. Four of us went on the first crossing, to be followed by the other four in the second crossing. Those on either shore who were not in the boat, pulled on the cables to pilot the scow across the river. This proved to be ab adventure due to the strong rapids currents in the river!
We learned that the tufa mounds were thought to be a sacred place and efforts to preserve their integrity arise from their geological and their cultural significance. The tour was tightly scheduled and we were required to remove our footwear to walk on them; only four people were allowed at one time. There is a another reason that the tours only occur at two times in the day. The country we are in is a significant summer habitat of the grizzly bear. This is due to the fact that their is an abundance of buffalo berries, the primary food source for the bear in the summer months (July and August). Tours at 8:00 a.m. and 1:30 p.m. have minimal impact on the bears, because they are more likely to be active in the early mornings and the later afternoons. Interestingly, the presence of a bear or evidence that a bear is in the vicinity means the cancellation of the hike, not only because of the safety of hikers, but also so that human activity will have low impact on the bears.
We arrived back at camp at about noon, just in time to see the "Rub-a-Dub 8" raft head down the river. We made a quick lunch and were ready to move on ourselves by mid-afternoon. We had planned to make as much time as we could today, given that it was a reasonably good afternoon for paddling. We didn't get off the river until after 8:00 p.m., having made 30 kilometres down river. By the time we made camp, no one was particularly pleased with the spot chosen because of the wet location and because of the sandy conditions. The wet and the sand made for lots of mosquitoes and lots of dirt in the tents and other gear.