Temporary Closure of Dead Lake, Porcupine Lake and unnamed stream

Date Sept. 4, 2019
Media Contact: (435) 592-4866


DIXIE NATIONAL FOREST – The Utah Division of Wildlife Resources will conduct a native Bonneville cutthroat trout restoration project using the piscicide rotenone within the Mammoth Creek drainage on the Dixie National Forest, beginning September 9, 2019.

The project is identified as a priority for Bonneville cutthroat trout conservation in the conservation strategy for the species, which is designed to prevent the fish from being listed under the Endangered Species Act. The rotenone treatment is aimed to rid all species of fish in targeted streams, ponds, lakes and tributaries in order to restore the native Bonneville cutthroat trout to a portion of the Mammoth Creek drainage.

This treatment will build on restoration work already completed in Castle Creek and Lowder Creek, as well as nonnative trout removal conducted earlier this summer in Reed Valley Creek. When the entire project is completed nearly 30 miles of the Upper Mammoth Creek drainage will be restored for native Bonneville cutthroat trout.

Depending on their location, most rotenone drips will run for three to eight hours. Applying the rotenone this way will ensure that all of the fresh water sources are simultaneously treated. Charges for drip stations are calculated to apply the five percent active ingredient liquid rotenone at a concentration of 1.5 parts per million in the target area.

The active ingredient in liquid rotenone is a powder derived from the roots of South American plant. Rotenone is specifically poisonous to gilled organisms because it interrupts oxygen uptake from the water at the cellular level.

Although liquid rotenone is relatively benign to humans, fish treated with the chemical have not been cleared by the Food and Drug Administration for human consumption. For that reason, fish that die during the project cannot be salvaged.

After the rotenone has been applied, potassium permanganate, an oxidizing agent, will be applied to treated waters below the target area to neutralize the rotenone in those areas.

The 2019 area closure for Dead Lake, Porcupine Lake and the unnamed tributary to Mammoth Creek draining John L. Flat is Pursuant to Title 36 Code of Federal Regulations 261.50 (a) and (b), the following areas will be closed during the treatments for protection of public health and safety.

The area within 100 feet of Dead Lake, Porcupine Lake and the Unnamed tributary to Mammoth Creek draining John L. Flat and its tributaries upstream from the confluence of the Unnamed tributary to Mammoth Creek draining John L. Flat and Mammoth Creek, to the headwaters of the Unnamed tributary to Mammoth Creek draining John L. Flat and its tributaries, located in T36S, R8W, Section 35 and 36 and T36S, R7W, Section 31, Salt Lake City Baseline and Meridian.

The temporary closure order is anticipated to be cancelled September 12, 2019 for the project area.

For more information on this project please contact Michael Hadley, Southern Region Aquatics Biologist, Utah Division of Wildlife Resources (435) 691-2204 or Mike Golden, Dixie National Forest Fish Biologist, (435) 865-3700.

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