At Redridge Falls, the Salmon Trout River cascades through the legendary Redridge Steel Dam. The waterfall is dependent on the water level; it roars to life in the spring and after heavy rains, but disappears entirely during dry periods.
Exploring the Redridge Steel Dam
From the Redridge Dam parking area, a short, steep trail runs down to the river. There might be a few local anglers fishing for steelhead, but you’re more likely to have the area to yourself.When the water is low, people like to climb around on the dam. (There are stairs built into the cement base, so it’s not nearly as scary as it looks.)
Follow the trails up and over the dam — or take the easier route from the parking lot — and you’ll find a small lake. It’s all that’s left of the massive reservoir that once fed the local stamp mills. Keep an eye out for the remains of the old timber dam (read more below) just upstream of the steel dam.
How to Get to the Redridge Steel Dam
The Redridge Dam is located about 11 miles west of Houghton, Michigan.
Directions to the Redridge Steel Dam]
- From downtown Houghton, head east on Shelden Avenue
- Continue onto M-26 east by the Portage Lift Bridge
- Turn right on Houghton Canal Road
- After 4.2 miles, turn left onto Liminga Road (across from Schmidt’s Corner Bar)
- Drive 5.9 miles to reach the dam
After you pass through the tiny community of Redridge, cross the bridge over the river and look for the small dirt parking area on the left.
Redridge Steel Dam GPS coordinates (parking area): 47.149727, -88.765765
About the Redridge Steel Dam
The Redridge Steel Dam is one of just two surviving steel dams in the United States. (The other, Ashfork-Bainbridge Steel Dam, is located in Arizona.) At 1,006 feet long and 74 feet tall, it’s also the biggest steel dam ever built.1 There was a third steel dam on Hauser Lake in Montana, but it washed away in 1908, a year after it was built.
When you’re standing below this massive metal structure, keep in mind that it’s a gravity dam; it’s held in place by its own weight, eliminating the need to install anchors in the bedrock. Steel was an unusual choice for a dam when construction began in 1900, but it was cheap. It was also easier to transport than other building materials — a critical factor, given the remote location.
The Redridge Steel Dam (or the Redridge Dam, as Keweenaw locals call it) created a 600-million-gallon reservoir on the Salmon Trout River. It provided water for two local stamp mills until the 1920s. After the mills closed, the mining companies opened the valves and abandoned the dam.
Flooding at the Redridge Dam
On April 13, 1941, heavy rains and spring snowmelt broke up a series of beaver dams upstream. The resulting flood of water sent a cascade of logs and debris rushing through the dam, destroying the spillway. It’s hard to imagine today, but water spilled over the top of the dam, filled the ravine, and came within 2-4 feet of destroying the road above. Check out a photo of the flooding in the Michigan Tech Digital Archives.
Flooding at the Redridge Dam continued to be an issue for years. One former student at the Redridge School remembers classes being canceled in the 1960s when the water levels rose too high. (The school is still standing; look out for the two-story blue building just before you reach the dam.)
In 1979, the Copper Range Company cut holes in the back of the dam to reduce the stress on the structure — they’re visible in the photo below. Today, Redridge Falls pours through those holes when the water level rises.
The catastrophic 2018 Father’s Day flooding in the Keweenaw put additional stress on the Redridge Steel Dam. (Jason Asselin captured some remarkable footage that day.) It also saved Freda Road, according to Michigan Tech geotechnical engineer, Stan Vitton. Senior design students at Michigan Tech estimate that the dam stopped nearly 750 million gallons of water during the flood.2
Why Was the Redridge Steel Dam Built?
The Redridge Steel Dam was built to provide water for the stamp mills for two Keweenaw copper mines.
In the early 1900s, copper mining was a booming industry in Michigan’s Upper Peninsula. Mines processed the rock in stamp mills, which produced a waste material called stamp sand.3
For decades, local mines had been dumping stamp sand into the Portage Canal. Around the 1890s, the War Department forced the mines to move their mills to Lake Superior because the mine tailings were clogging the shipping channel.
Since stamp mills require a great deal of water, the Salmon Trout River at Redridge was the perfect location. In fact, the Atlantic Mining Company had been using the river for its stamp mill since 1895.4 When the Baltic Mining Company moved in, the existing timber crib dam was too small to support the demand.
The two mining companies came together to build the Redridge Steel Dam. They hired J.F. Jackson, an engineer at the Wisconsin Bridge and Iron Company, to design the structure. A hydraulic engineer named F. Foster Cromwell was the consulting engineer for the project.
Redridge Timber Crib Dam
When the Atlantic Mining Company first moved its stamping operations to Redridge, it built a timber crib dam just upstream of where the Redridge Steel Dam is today. This type of dam looks something like a log cabin. The one at Redridge features multiple square cells, each filled with sand and/or rocks to add weight and distribute the force of the water.5 You can still see the individual cells, or cribs, today — and when the water is low enough, you can walk across the beams.
After the Redridge Steel Dam was built, the water completely covered the timber dam. (Looking at the photo above, that gives you some idea of how big and deep the reservoir was.) It reappeared again when the reservoir was drained, and remained standing until 2004. At that point, the Michigan Department of Environmental Quality decided that the aging timber dam presented a significant safety hazard and issued a “repair, replace, or removal” order.
Though Stanton Township considered options for repairing and rebuilding the historic dam, the cost estimates ($300,000 to $1 million) were too high. Instead the township worked with Michigan Tech to remove the top section of the dam to lower the water level and reduce the risk of failure.
As of 2023, both the Redridge Steel Dam and the lower section of the timer dam have been deemed safe enough to remain standing.
Sources
1. Bishop Eckert, Kathryn. “Redridge Dam.” SAH Archipedia, Society of Architectural Historians and the University of Virginia Press. Accessed 14 May 2023.
2. Keranen, Angela. “Michigan Tech: Tradition, innovation and an extraordinary Winter Carnival.” Civil, Environmental, and Geospatial Engineering News, Michigan Technological University, 4 Feb 2021. Accessed 15 May 2023.
3. Mills, Allison. “Geoheritage: Stamping Through History.” Unscripted Research Blog, Michigan Technological University, 1 Sept. 2016. Accessed 14 May 2023.
4. “Atlantic Stamp Mill Operation.” Stanton Township. Accessed 14 May 2023.
5. Schuster, Robert L. and Steven M. Smart. “Timber Crib Retaining Structures.” Transportation Research Board Special Report, no. 160, 1975