Crews filling sinkholes at former Tumalo mine site

(Update: Works begins to fill sinkholes)

Work was underway Tuesday to fill dozens of sinkholes on a popular Tumalo recreation site where winter weather has created some dangerous conditions and closures at the former pumice mine..

The 540-acre parcel that’s a popular hiking and dog-walking spot for neighbors developed numerous sinkholes this wet, snowy winter, prompting the emergency posting last Friday of “no trespassing” signs in some areas.

“We’ve seen walkers cutting across and I’m worried that if they’re up here letting their dogs run,” Ken Rieck, manager of the Tumalo Irrigation District, which owns the property, said Tuesday. “A dog or pet could fall into a hole, and then the person is going to try to go rescue their pet, and they’re going to get trapped — especially if they’re alone and nobody knows what happened.”

The first set of signs were torn down and trashed over the weekend, and Rieck said Monday the whole area might have to be closed if that keeps happening.

“You don’t want to be anywhere close to any of these sinkholes,” he added during a visit to the site Tuesday. “I know they’re kind of an attractive nuisance, and people want to go and take picture of them. I’d recommend that you just stay way away.”

Reclamation work was completed in 2009 at the 540-acre former Cascade Mining Pit on Tumalo Reservoir Road, where pumice was mined for many decades, Rieck said.

Rieck said he didn’t see any sinkholes that were more than five or six feet deep, but he hadn’t seen them all up close enough to measure. He estimated the closed areas of the former mine total more than 130 acres.

The district asked in a news release Monday that people trespassing on unclosed areas “please respect the signs and stay well away from any potential sinkhole activity.” Rieck urged visitors to stay on the cinder roads through the property.

Officials also asked visitors to report any new sinkholes or other hazards outside the newly posted areas by calling the district office at 541-382-3053.

Rieck said the first set of warning signs were posted Friday, but “were torn down and trashed over the weekend.”

“We are trying to not have to close the whole property, but trashing our signs is not helping to keep it open,” he said. “All the signs have been replaced again today (Monday).”

Rieck added, “We generally try to keep the property open for recreation. Someday, it’ll be developed.”

But at present, “a lot of people treat it as public land,” Rieck said, and may mistakenly believe that’s its actual status.