BRAD HORN/Nevada Appeal Nevada Department of Transportation workers put the finishing touches Friday on Highway 342 north of Silver City where a 30-foot sinkhole closed the route to Virginia City for nearly a week.
Visitors heading to Virginia City will have an easier time this weekend as Highway 342 opened Friday evening.
The state-maintained road was closed early Monday morning after a sinkhole opened up over an old mine shaft. The hole, measuring about 30 feet in diameter with a depth of about 25 feet, was about a half-mile north of Silver City and covered more than half of the northbound lane.
Traffic to and from Virginia City had been rerouted to the Highway 341 truck route.
Peter Booth, an engineer with the Nevada Department of Transportation, said the sinkhole was not likely to open again.
"We're confident it will support the roadway, that we won't have any more failures in that area," he said. "We believe that mine caving in was a result of some timbers placed on top of the mine opening and we believe those timbers rotted out."
NDOT spokesman Scott Magruder said the $30,000 contract was awarded to MKD Construction Inc. of Carson City.
Booth said loose dirt and debris were removed from the hole and concrete road barriers, also known as Jersey barriers, were installed as a bridge to support the roadway.
"The mine shaft was 2,300 feet long but went straight down about 300 feet," he said. "We basically built a bridge underground."
After the concrete beams were installed, Booth said, rock and fill were used to close the hole and cold millings, a clean gravel, was laid under the road bed. Then a temporary road bed was installed
Magruder said when the weather warms up, the asphalt can be replaced.
The sinkhole was discovered by NDOT snowplow driver Alfie Reiss at 3:15 a.m. while he was checking the highway before his shift ended.
Magruder said the sinkhole was caused by water saturation after a weekend of heavy rain and snow.
Booth said sinkholes were a fact of life in the historic mining district.
"Anywhere, anytime in Virginia City, because there are thousands of miles of old, abandoned mine shafts," he said. "But we're confident this one will hold."
-- Contact reporter Karen Woodmansee at kwoodmansee@ nevadaappeal.com or 882-2111 ext. 351.