The Toklat is the largest braided river that is crossed by the Denali Park Road. The vast plain of cobbles, gravel, sand, and silt deposited by the river is a renewable resource. Every other year, large machinery excavates 22,000 cubic yards (17,000 m3 ) of gravel from the Toklat riverbed for use in resurfacing the park road. Geology and maintenance staff design the excavations to mimic braided river channels in order to minimize impacts on natural processes and visual aesthetics. The park road loses material over time because of erosion, slumping, and dust, and this material must be replaced to maintain a safe surface for travel. Toklat gravel provides a local source for the material, rather than it being imported from outside the park. This reduces the number of vehicles traveling the road. Using locally-sourced gravel also prevents the spread of invasive plants whose seeds commonly hitchhike to new places in loads of soil and gravel. Finally, because the gravel does not need to be purchased and transport distances are shorter, the park saves money and produces less carbon dioxide emissions.
Many of the rivers and streams in Denali are braided, consisting of many short-lived channels weaving across a wide bed of cobbles, gravel, sand, and silt. What you are seeing is not just a “dry phase”—water almost never flows over the entire width of a braided river at any one time. Braided rivers and streams occur within watersheds where relatively large amounts of sediment are transported by relatively small amounts of water. Because glaciers are such powerful, the braids of an unnamed stream weave through Denali’s lush landscape. agents of erosion and therefore create large amounts of sediment, braided rivers are normally, although not exclusively, glacially-fed. At higher water levels, braided rivers can transport larger amounts of sediment from upstream, but they deposit that sediment when the water level drops. The deposited sediments force the water to move to new paths of less resistance. In Denali, this often happens on a diurnal basis, with higher water flows and sediment transport occurring during the heat of the day when snow and ice are melting and contributing to flow, but it also varies seasonally and in response to storms and glacial processes.
Safety in the Park:
Denali National Park is a wild, wonderful place to visit, but it is important to know the hazards before you head out into the park. Explore the sections below to prepare yourself for your Denali visit.
Wilderness Safety:
Even experienced wilderness travelers can have an accident that results in an injury or even death. Accidents are possible anywhere - so the information below is important to all visitors. You may also want to read the safety information in the park newspaper to prepare for your trip.
- Wildlife
Wildlife can behave unpredictably. Do not intentionally approach wildlife. Read the Wildlife Safety section for more details.
- Plants
Do not eat berries unless you know what they are, and are sure you have no allergy to them. There are no poison oak, sumac or ivy species in the park, but some other plants can cause allergic reactions, such as cow parsnip.
- Hypothermia
Hypothermia is always a factor in the subarctic. Rainy, chilly days are normal in summer. Dress in layers, preferably made of wool or synthetic material that is able to insulate you even when wet. Bring rain gear or an umbrella.
- Injuries
Be wary of falls. Most of Denali is trail-less, and long hikes are often on a route of your own choosing. If you are hiking up a rocky hill or mountain, be careful of your footing. More people die from falls than any other cause in the park.
- Don't go alone
You should always hike with at least one other person. Even then, make sure someone else knows where you're going.
- Know thyself
Even if you plan to stay on trails or the park road the entire time you are here, keep in mind that even the entrance of Denali is several hours from the nearest hospital. Locations on the park road (i.e., during a bus trip) are even more remote. If you know you have a medical condition, such as a heart problem, talk to your doctor about your travel plans to see if there is anything you should do to ensure a safe trip.
Wildlife Safety:
Seeing a wild animal in the backcountry can be an incredible experience. But knowing how to behave in an encounter scenario might make all the difference. Whether it's a moose, a bear or some smaller animal, be prepared to react accordingly. Bear spray is proven to be highly successful at stopping aggressive behavior in bears. Learn more about using bear spray.
Please visit https://www.nps.gov/dena/planyourvisit/safety.htm for more information.
Logging Requirements:
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Why is the Toklat River considered to be a braided river? Please back your claim with evidence found at the GZ, the nearby information plaque, and the information above.
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Go down toward the Toklat riverbank. What is the average size of the sediment found? What does this tell you about braided rivers?
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As of June 2019, earthcaches are now allowed to have a required photo logging task. Please provide a photo of yourself, your GPSr, or a personal item that proves that you have visited this site. Please post this in your log.
**Please complete all logging tasks to log this earthcache**
Sources:
https://www.nps.gov/dena/learn/nature/upload/Denali-Geology-Road-Guide.pdf
https://www.nps.gov/articles/denali-upwelling-areas-toklat-river.htm
https://www.nps.gov/dena/learn/nature/upload/Denali-Geology-Road-Guide.pdf
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