Summer 2009: Aerial Spraying of Badlands National Park

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Date: July 6, 2009
Contact: Brian Kenner, (605) 433-5260

BADLANDS NATIONAL PARK, S.D. — Aerial spraying of herbicide for management of Canada thistle will begin Monday, July 6th. Spraying should be completed by July 20th depending on weather. Spraying will take place in wilderness areas of Badlands National Park where other mechanical methods of weed management and herbicide application are restricted. Approximately 5,000 to 6,000 acres of scattered Canada thistle patches will be sprayed within the 64,000 acres of wilderness.

Badlands National Park has contracted with Scott’s Helicopter Services Inc. from Le Sueur, MN to make the aerial application. The contractor will be flying a Bell 47 Soloy helicopter and will apply herbicide from a height of 10 to 15 feet above patches of Canada thistle.

Milestone herbicide will be applied. Milestone is a relatively new herbicide produced by Dow Chemical Co. It provides effective control of Canada thistle without damage to native grasses and with little damage to native forbs, trees and shrubs. Low level boom spraying from a helicopter following label limitations will allow for maximum coverage of infested acres with minimum impact to non-target species.

The Environmental Protection Agency (EPA) considers Milestone to pose "no real health hazard" and does not classify it as a Restricted Use Pesticide. It is registered under the EPA's Reduced Risk Pesticide Initiative. This designation is made for chemicals that demonstrate lower risks to humans and the environment than marketplace standards. Milestone is applied at a low rate, 5 ounces per acre, which means less chemical added to the environment. It is considered practically non-toxic to aquatic organisms, fish, and birds, breaks down to natural soil components and is non-volatile.

Visitors should not be overly concerned about exposure to Milestone. They should avoid Canada thistle patches. Direct exposure may cause moderate eye irritation. If they feel they have come into contact with Milestone, they should wash hands and face before eating and wash clothes at the first opportunity.

We recognize that a helicopter will be an intrusion into visitors' wilderness experience, but we feel the need to control Canada thistle and reduce its impacts on the park's native prairie warrant the intrusion.

This project is funded by the President's Centennial Initiative for the National Park Service.

For more information, please contact Brian Kenner, Director of Resource Management at (605) 433-5260.

Last updated: April 10, 2015

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