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The stubborn simian still refuses to give up its grip on the Rims.

On Saturday, despite a blasting attempt, the large sandstone formation east of Zimmerman Trail called “Monkey Face” for its canny resemblance to an ape, refused to come down. The blast did dislodge portions of rock behind and on top of the huge slab.

Work was done by crews from GeoStablization International of Grand Junction, Colo., in conjunction with the city’s consultant, Terracon; Greg Rogers, an explosives expert from Stevensville; and city officials.

The crew was more successful in bringing down a large rock, called Rock 5.2, east of Monkey Face. Workers followed up by using an airbag to remove remaining rock segments, as well as scaling, or cleaning up other unstable rocks by hand.

Earlier in the day, workers from the landslide remediation company did additional work in the area west of Zimmerman Trail. Blasting helped eliminate some overhanging rock.

On Friday afternoon, crews managed to dislodge a formation east of Monkey Face called Shark’s Tooth. And even though the front of Monkey Face didn’t budge on Saturday, the afternoon blast removed some of the rest of it.

“We made very good progress today,” said Dan Nebel, a Terracon geologist.

He was pleased with the work done west of Zimmerman and much of what was done to the east.

He admitted some disappointment that for the second consecutive day Monkey Face couldn’t be wholly brought down.

But progress was made, even though it’s not obvious by looking at the rock.

“You can’t see it from the front but they did take off over half of it on the back side,” Nebel said. “We got rid of a lot of weight. The blast also took off quite a bit up on top, so it gained a little more stability than it had earlier.”

Crews will resume work on Tuesday, he said. The team will evaluate the best next steps to take. That could mean taking the rest of the slab apart piece by piece, using pillows to push it apart or using machinery to push parts of it over.

“We’ll be monitoring it over the weekend,” Nebel said.

He thinks work on Monkey Face will be done in another day or two. Then it will take three to five days to do scaling and clean-up.

The Zimmerman Trail rockfall remediation project remains ahead of schedule, Nebel said. The contract called for work to be completed by June 13, and he believes it will likely be done before then.



General Assignment and Health Care Reporter

General assignment and healthcare reporter at The Billings Gazette.