After years of work and $37 million spent, Blue Earth County Road 1 nears completion

Oct. 1—One of the most complex road projects ever undertaken by Blue Earth County is about a month from completion after eight years of on-again, off-again work on the scenic route south of Mankato.

County Road 1, including the portion once known as state Highway 66, has undergone a nearly $37 million transformation from the Mankato city limits, past Mount Kato, under the Red Jacket Trestle, out of the Le Sueur River Valley, through Good Thunder and past farmland to the southern county line near Lura Lake in rural Mapleton.

"We're getting there. Light at the end of the tunnel," said Ryan Thilges, who has been working on the project since before he was promoted to Blue Earth County Public Works director in 2016.

The nearly 12-mile portion of the road from west Mankato to Good Thunder has long been a popular route for drivers and motorcyclists looking for a pretty drive, particularly during the fall colors season. But leaf peepers will have to wait one more year to return to that tradition because construction isn't expected to be completed until the leaves have fallen.

"We're anticipating it will be early to mid-November," Thilges said.

The road is open to Red Jacket Valley County Park but is blocked just south of there as Mathiowetz Construction puts the final touches on the reconstruction of County Road 1 through the tight corridor along the Le Sueur River and up the narrow ravine to County Road 9 (the road leading to Rapidan from the east).

The expected finishing date is a month to six weeks later than the Sept. 30 date that was the target in April when work was set to resume but was hampered by a cold and wet spring.

When the entire road is open, commuters from southern Blue Earth County, farmers bringing crops to market and scenery seekers will find a safer road designed for higher speeds with wide shoulders, better sight lines and softer curves. There will also be better drainage and less erosion along the steep hillsides beside the highway.

Driving from Mankato, the first section is actually Phase II of the multi-phase project. That $10.9 million phase — which included towering "big block" retaining walls — was constructed in 2018-19 and was the winner of the Minnesota County Engineers Association statewide Project of the Year contest.

Phase III is the section between County Road 90 and County Road 9 that is being finished now at a cost of $16 million after two years of construction. That segment, running through a narrow and rocky stretch of topography, features a specialized retaining wall that required a construction crew from Colorado.

The "soil nail wall" technique involves stabilizing soils with facing-material attached to the side of an erodible hill with long steel bars "nailed" deep into the hillside. The final surface of the facing, which stretches for about 1,500 feet on the upper reaches of the ravine, is being shaped and dyed to resemble cut limestone.

That will match the quarried rock walls at the nearby historic Red Jacket Trestle.

"We wanted to make sure we could kind of preserve the heritage of that corridor," Thilges said.

The uncommon construction techniques required on that segment of the road — along with the work on the constricted, winding section just south of Mankato's Carney Avenue — created enough challenges to draw repeated tours by engineering classes from local colleges. And it made for one of the most elaborate projects the county has undertaken.

"This is up at the top of the list," Thilges said.

Phase I, running from County Road 9 to Good Thunder, was a more traditional project for southern Minnesota highway engineers.

"Straightening and widening — we do a lot of that," he said of the 2016 project.

All of the work between Good Thunder and Mankato has been financed by the state of Minnesota — "turnback funding" provided to ensure Minnesota Highway 66 was in excellent shape for years to come after the Minnesota Department of Transportation asked Blue Earth County to take ownership of the route.

MnDOT and then-Public Works Director Al Forsberg negotiated the repairs and upgrades that the state would finance prior to the County Board agreeing to the turnback. Initially predicted to cost about $20 million, the final price turned out to be $33.1 million as inflation added to the cost and a few unforeseen complications were discovered.

In return for the funding, MnDOT is absolved from future responsibility for maintaining Highway 66, which is now called County Road 1.

In addition to the former Highway 66 portion, the original County Road 1 was improved in 2015 south of Good Thunder at a cost of $3.7 million in county highway funds.

That work also involved widening shoulders, improving sightlines, flattening sharp curves and reducing steepness of ditches in the section between Good Thunder and Highway 30. South of Highway 30, construction was limited to repaving the driving surface.

But the result come November will be a top-quality north-south road from one end of the county to the other — a central transportation corridor to complement north-south roads like Highway 169 on the county's western side and Highway 22 on the eastern end.

Because the turnback funds were in addition to the county's regular highway repair program, it represented a massive increase in the workload for Thilges' staff over several years.

"Our guys have done a great job," he said.

And he's confident highway users will come to the same conclusion when they get a chance to take a look — especially when autumn fall-color rides are planned in 2023.

"It'll be a nice drive," Thilges said. "It'll be more of a bike-friendly roadway, too."