REDDING, Calif. -- Lake Shasta Caverns will temporarily close its tours early next year to work on their largest capital investment project since the early 1960s.

Matthew Doyle, general manager of the caverns, said starting January 6 and ending in March 2025, crews will be upgrading the lighting system within the caves. Doyle said the previous lighting system is nearing the end of its lifespean.

"With our existing lighting system nearing the end of its lifespan, we have decided to focus on a major updated to this system, while continuing to further our conservation efforts in the cave. At the same time, we will also create a new and truly engaging experience for our guests," Doyle said in a news release on Friday.

Cavern officials said the new lighting system reduce power consumption by nearly 80%, allowing them to switch from diesel generators to solar power. The new lighting system, called 'illuminaries,' will also prevent the unnatural growth of lamp flora -- algae, mosses and bacteria that grow around permanent light sources -- and benefit the bat habitat within the caves.

"Once completed, guests on the tour will have an entirely new experience with the dynamic lighting that will be controlled by the cavern tour guides," Doyle continued. "The illuminaries will fade in and out, shift colors and help the guides keep the focus on the tour."

Doyle said the largest room in the caverns, The Cathedral Room, will feature a light and sound show that poetically narrates the caverns' history from formation, to discovery and current operations.

Cavern officials said Lake Shasta Caverns will become the second cavern in the United States to implement this state-of-the-art upgrade, following Natural Bridge Caverns near San Antonio, Texas.

Affordable Electric and Germany-based Cave Lighting are collaborating on this project, with personnel from Shasta County, Romania, Slovakia, Spain and Germany contributing to the development, programming and installation of the system, according to Doyle.