VIDEO: Highway officials aiming for the weekend of Sept 16 to partially reopen Hwy 97 at slide site near Summerland

When the slide came down and forced the closure of Hwy 97 north of Summerland, the boulders and debris on the highway was substantial.

But there is exponentially more material that's shifting on the slope above where an ominous crack is now visible, separating the front portion of the wall of rock from the mountain behind it.

Officials are hoping to have the slope stabilized enough to allow them to reopen to single-lane traffic by the Sept. 16 weekend.

Ministry of Transportation's Steve Sirett said it's that break in the hillside that engineers are most concerned about.

"That crack specifically is the one that first alarmed us," said Sirett, not discounting the slide itself.

It's concerns about the separation in the rock face that have caused the closure to remain in place as long as it has.

"What that tells us is a large portion of that mass is moving," he said.

"We're seeing about 15 to 20 millimetres of movement on that slide as a result of that crack."

It's the same slide area that forced a closure of the highway for months back in 2008.

"We drilled and blasted to take some of the pressure off of the slide at that time until a point where we saw it stop moving," said Sirett.

"It's been about 15 years since that occurred and now it's reactivated again."

While engineers work on how to stabilize the slide, crews have installed a concrete lock block wall at the base of the slide to protect traffic once it's safe to let it through.

Safety is paramount, but there are pressures to get traffic moving again.

"Our focus is always to get traffic moving on the highway as quickly as possible, but obviously that has to be done when it's safe to do so."

Crews are hoping a berm that's being built at the base of the slide will help stabilize things above.

"With the next step getting open to two-lane traffic," said Sirett.

"But that's down the road once we have a better understanding of how the slide responds to the construction of the berm."

So for at least 10 days, the preferred route between Kelowna and Penticton is currently the 201 Forest Service Road which is accessed near McCulloch Road East of Kelowna.

In Penticton, the route is accessed off Warren and Carmi Avenues.

It's a gravel road, but it's been upgraded to better handle the traffic.

Sirett acknowledges that the plans to reopen to single-lane traffic in mid-September are subject to change.

"That's our target, but we are working in an active slide zone," he said.

"If additional material comes down, that would absolutely impact when we do get open."