Contractors will soon start blasting part of Schaar's Bluff to create a scenic trail overlooking the Mississippi River in Spring Lake Park Reserve.

The 4.3-mile section of trail northwest of Hastings will be part of the Mississippi River Regional Trail though Dakota County, one piece of a path stretching from the river's headwaters in Itasca to the Gulf of Mexico.

"The Mississippi River Regional Trail offers unique opportunities for anyone to experience the Mississippi River and also Spring Lake," Parks Director Steve Sullivan said in a recent presentation to the County Board.

The county is adding two bridges over ravines that will span 250 and 400 feet and have scenic overlooks. The trail will be paved and include interpretive signs. It will cost $8.9 million to build the 4.3-mile section of trail, county staff said. That sum includes restoration of prairie grass, trees and shrubs.

The route is scheduled to open for cyclists and hikers in fall 2016.

Rock excavation is anticipated to start in the next two weeks, though a firm timeline has not yet been decided, County Construction Engineer Ross Beckwith said.

The Nininger Township Board approved a mining permit application Tuesday night for specialty contracting company Veit to blast the trail along the bluff.

The excavation is expected to take three to four months to complete.

Neighbors will likely not even notice the blasting, Beckwith said, adding, "It's pretty minor, in terms of noise."

"People think of half of a mountain flying off somewhere, but it's really precision cutting in rock," he said.

Officials will conduct seismic and vibration monitoring during the process.

A model airfield next to the Schaar's Bluff trailhead is closed during construction and will become a rock processing and storage site.

The county does not know when the airfield will reopen for public use. Contractors have up to three years to restore the airfield site after the trail opens in 2016.