Explosive morning: WSDOT destroys car-sized boulder in Tumwater Canyon

LEAVENWORTH – On the morning of Feb. 6, Washington State Department of Transportation’s (WSDOT) avalanche control supervisor employed a controlled explosion in Tumwater Canyon, shattering a boulder about the size of a car. The blast reverberated through Leavenworth, shaking houses and startling residents.

The rockfall was discovered by one of WSDOT’s crew during their routine morning check at approximately 4:30 a.m., near milepost 98 on Highway 2. According to WSDOT, the crewmember found a rockfall in the traffic lane consisting of gravel to softball-sized rocks, with the largest boulder being about the size of a car. 

“Usually crews are able to plow or scoop up the rock, but when the boulders are too large for a loader bucket, occasionally one of our specially trained crew will use a device that employs a small amount of explosive placed strategically on the rock to break it up into smaller pieces,” said Lauren Loebsack, Communications Manager of WSDOT’s North Central Region, in an email to Ward Media.

According to Loebsack, wet weather after a hard freeze can exacerbate rock fall from slopes by causing slope materials to loosen up. There are jersey barriers and netting in known problem areas, which the crew patrols frequently. However, drivers should be alert when traveling in these areas and not attempt to drive over fallen rocks.

“Further, if you do see a rock fall, do not get out of your car to clear it, as this can create an additional safety hazard. We ask that you instead find a safe place to use your phone and call 911; that will mean [Washington State Patrol] or WSDOT staff will be dispatched to clean it up and we can better track the occurrence of rock fall. Larger mitigation projects are planned based on a formula for need so the more reports of rockfall we have, the better case we can make for mitigation projects to reduce the issue,” said Loebsack.

Taylor Caldwell: 509-433-7276 or taylor@ward.media