One hundred years ago, a switch was flipped at PG&E's Pit 1 Powerhouse in eastern Shasta County, sending 220,000-volts of electricity to a substation 202 miles away in Vacaville. At the time, it was the longest and highest-voltage transmission power line in the world. The powerhouse, power line and substation would help drive California’s economy by enabling clean and cost-effective power to travel great distances, and usher in more hydroelectric powerhouses and a network of long-distance transmission lines. Both facilities are still in operation today and continue to be a critical gateway for power serving the San Francisco Bay Area.