The City of Missoula, Montana is proposing to breach the 15-foot-high earthen dam it owns on McKinley Lake in the Rattlesnake Wilderness to the north. The dam is in poor condition and no longer used for its original purposes of downstream irrigation and municipal use. Missoula also owns nine other wilderness dams found on lakes deep in the Wilderness. Removing the dam is a great idea. But it is also important to the integrity of Wilderness how the work gets done. 

Removing the dam is a great idea. But it is also important to the integrity of Wilderness how the work gets done. The city's proposal calls for using a helicopter to deliver a motorized drill (for drilling holes in the earthen dam for placing explosives) and a few other small pieces of motorized equipment, allowing workers to drive motor vehicles on an old jeep trail for a couple of miles within the Wilderness to shorten the hike to the dam, and using pack animals to haul other supplies to the workers while the work is in progress. It is entirely possible to do the work the "wilderness way," that is, accessing the site on foot or horseback, packing in all supplies and using traditional, non-motorized tools to breach the dam. The dam was built without motorized equipment, and much larger projects in Wilderness have been accomplished without modern machinery.

The Forest Service justifies the use of helicopters and other motorized equipment arguing the work must be done in one season and other options don't offer that possibility. However, an independent engineer with decades of experience using traditional skills for trail and other projects in the backcountry has estimated a crew of ten could complete the project in no more than 30 days and at a fraction of the cost the city has estimated it will spend on its current plan.



The city owns the dam and has a 100-year-old easement that gives it the right to maintain or remove the dam. The legislation that established the Rattlesnake Wilderness granted the dam owner the right to "necessary motorized use" over existing trails to operate and maintain the dam. But since the dam is on national forest land, the Forest Service has some say in how the dam is accessed and the kinds of work that is done on site.

The Forest Service has the authority and responsibility to set the terms and conditions for access to the dam and what occurs around the dam in the course of its removal. As the public stewards of the Rattlesnake Wilderness, the Forest Service needs to encourage the city to explore and implement feasible means of non-motorized alternatives to breach the dam and to provide assistance to the city in doing so. This is especially important because the city owns dams on seven other small lakes in this Wilderness, and this McKinley Lake project is presented as the pilot project for dealing with the other dams. As a pilot project, it is especially important to establish the feasibility of doing the project the right way in Wilderness.

• Read our comments to the Forest Service (August 2023)
• Read our comments to MT DCNR (May 2023)
• Read our comments to the Forest Service (April 2023)

Additional information

• Power tools or pack mules: Wilderness dam destruction debated (Missoulian, August 2023)

Photo: City of Missoula