From quarry to highway

By Margaret A. Ontl

Countless miles of roadway in western Wisconsin, thousands of yards of river and stream banks, ribbons of asphalt and landscape stone all have originated in a quarry in the city of Hudson.

What is currently the Milestone Materials' Mimbach Quarry, covering 130 acres and stretching for nearly a quarter-mile, was first used in 1948. In 1971-72 it was in full production, providing materials for construction of the new interstate bridge in Hudson. In 1996 the Mathy family purchased it. Today it is generating nearly all of the material being used on the Highway 35 project from River Falls to Hudson.

Currently the trucks hauling their materials exit onto Tower Road to the south, but the long-term goal is to create access to Hanley Road and close the Tower Road access.

"We expect it to operate another 20 years," said Dick Erickson, area manager for Mathy Construction, owners of Milestone Materials. "It is good hard stone. It is one of the few good limestone quarries in the area."

The production process starts on the north end with drilling and blasting the limestone off the face of the quarry. The company operates three seismographs, one in the industrial park, one at St. Croix Meadows and a third that changes location. Neighbors are notified 24 hours in advance of blasting.

Once the rock is loosened from the face, it starts its journey to the other end of the pit. Large boulders are separated out and broken down by a hydraulic hammer into product used for rip rap. The rest continues through a series of screens, crushers and washers to become base course, three-eighth-inch chip stone for seal coating, concrete stone and manufactured sand. The quarry can create just about anything the contractor wants and meet the job specifications by changing screens.

The quarry provided 450,000 tons of base course for the Hwy. 35 project and 80,000 tons of concrete stones.