Yosemite NP improvements

Project Description: This is the first phase of a two-phase project.
It will complete the compliance, design, and contracting support for
the project to replace the overhead power transmission lines with
underground power and communications to Wawona Tunnel. This project
will replace the failing overhead components with a duct bank system
that will connect to a recently constructed duct bank at Bridalveil
Falls and continue the duct bank up to the Wawona Tunnel. Three
replacement 12kV power lines and the replacement communication line
will be installed in the new duct bank. The out-of-date Supervisory
Control Acquisition Data (SCADA) System will be replaced with new
hardware to properly control all tunnel ventilation and lighting. The
project will also replace, in-kind, existing surface mounted armored
power and communication cables that continue from the Wawona Tunnel
location up to the Turtleback Dome Communication Tower site. This
project includes replacement of a generator, switchgear, tra .....

In addition, an underground transmission system will improve the
natural scenery and setting in the area, as well as reduce fire danger
due to downed lines. This project reduces tunnel closures that require
visitors and first responders traveling between Wawona and the Valley
to use the alternate route Highway 140, adding hours to their travel
and significantly impacting emergency services and visitor
experiences.

you can search the document for 'wawona tunnel' to find rest of the details