Officials have reached another milestone at the Sanford Underground Laboratory in Lead. They've regained secondary access to the lab where scientists from around the globe plan to do research.

Crews have been using the Ross Shaft at the Old Homestake Mine to travel underground, preparing the Sanford Lab. But now, they have another option; for the first time in six years, the Yates Shaft has been restored for use to the 4,850-foot-level.

"The main entries into the underground workings are the shafts and having two shafts is the main travelway underground," project manager John Mattheson said.

Matthesen says the effort to re-open the shaft was difficult due to a process of re-stabilization, but now, it's been secured and is ready to haul people and equipment deep underground.

Having two ways in and out of the 4,850 foot level is not only going to increase the speed at which this project progresses, it's also going to make it safer for workers to head underground.

"If one of the shaft's hoists went down, we'd have another way out. It's a big deal to us as far as the safety aspect of it," Mattheson said.

Providing easier access to the lab for workers, and another way out if necessary.