The Boise River Watershed is one of Idaho’s best-kept secrets. The Boise River winds through the heart of the City of Boise, Idaho’s capital city. There aren’t many state capitals that can boast of spectacular fly-fishing and floating in the very heart of downtown. A greenbelt system of parks and walking paths has provided scenic and recreational benefits to a sizable urban area whose residents cherish and nurture its health.
The river’s headwaters lie in the mountain range that stands as a sentinel to the north of the city. The North, Middle and South Forks of the Boise converge to form the Boise mainstem just 10 miles above town. All of the Boise River system offers wild and native trout and plenty of solitude and beauty. Partly due to its proximity to the largest population center in Idaho, the river system is utilized heavily as a recreational resource and is symbolic of what Idaho means to its citizens. This was not always the case. Many years ago, the river system served as the workhorse for placer, dredge, and hydraulic mining. The impacts from mining that occurred over 140 years ago are still felt in portions of the watershed.
Some segments of the river and its tributaries do not adequately support fish, wildlife or the recreational uses. A large tributary to the Middle Fork of the Boise, Mores Creek, is a prime example of where we have an opportunity to improve this watershed.
Mores Creek Project
The Mores Creek watershed was placered, dredged, and hydraulically mined in the late 1800s. Tailings piles, composed of cobbles with depths up to 15 feet, are scattered across open valleys of Mares Creek. These piles armor the streambanks, preventing channel migration, riparian vegetation growth, and limiting fish and wildlife habitat. At times, temperatures in the creek have reached lethal levels to fish. Hydraulically mined cliffs release massive amounts of sediment to a tributary of Mores Creek named Elk Creek. Elk Creek once provided native bull trout habitat and today is the source of Idaho City’s drinking water.
To date, over 17,000 cubic yards of tailings have been removed over a mile of Mores Creek. Large woody debris and boulder clusters have been added to provide complexity to the stream. Thousands of riparian plants have been planted by volunteers and over 700 students have participated in the project. This project has become an outdoor classroom for two local universities and the Idaho City high school. We have provided tours to legislators, foundation representatives, other elected officials and many others to highlight what can be done to decrease the scars from legacy mining.
Our project has expanded to incorporate private lands downstream. Multiple partners have joined and Trout Unlimited are working with land owners to incorporate instream habitat features in many locations throughout the watershed.
Future work includes focusing on micro habitat improvements where smaller, cooler tributaries enter Mores and Grimes Creeks. Trout Unlimited will monitor the success of creating a series of “oasis” features for the resident fish.
Monarch Stamp Mill Site
The Monarch Stamp Mill Site is located near the town of Atlanta. The Site is along the Middle Fork of the Boise River and was used for milling silver and gold ore from about 1865 intermittently through the 1920s and 1930s and perhaps longer. In the summer of 2006, Trout Unlimited began working with the Environmental Protection Agency to stabilize the banks of the river and pull back 23,000 cubic yards of mill tailings to an area beyond the river's reach. The tailings deposits had covered an area approximately 550 feet by 350 feet in area. The depth of tailings ranged from a few inches along the margins of the site to over 10 feet thick. These tailings were a source for continued erosion and downstream migration during times of peak flow. Also, elevated levels of arsenic and mercury presented a direct contact public health threat for recreational users of the site. Arsenic and mercury laden mine tailings were removed the river's edge. Clean fill was placed in soil lifts and planted with native willow poles.
The “clean” riverbank was revegetated with willows by Trout Unlimited volunteers and the EPA Boise Office. Vegetation was planted by volunteers the last two fall seasons, and the site is considered to be complete as of this year. We will monitor vegetation growth and consider this to be a successful partnership. Trout Unlimited and EPA will move to another site, and undertake willow weavings the fall of 2008.
Cleanup work underway at the Monarch Stamp Mill Site.
Trout Unlimited works in close partnership with many groups. TU could not be involved without the funding received from the Tiffany and Co. Foundation. This project will have direct positive affects on the historic town of Idaho City. Trout Unlimited is working with a wide range of partners that include the City of Idaho City, private landowners, the U.S. Forest Service, the West Central Highlands Resource and Development Council, The Wilderness Society, the Idaho Conservation League, and the Rocky Mountain Research Station. The Monarch Mine Tailings Site requires careful coordination with the Environmental Protection Agency and the U.S. Forest Service to ensure restoration can be completed after the removal and capping of the toxic materials.
For more information about the Boise River Idaho project contact Pam Elkovich by phone at (208)938-1110 x. 14 or by email.