This could be one of the oldest power lines in the USA, connecting a hydroelectric station to Los Angeles. These towers exist all the way from Bakersfield to LA. Around Bakersfield, one circuit is in service, in LA, the line has 2 circuits. South of Bakersfield you also can find original towers of the 150/220 kV power line from 1914.

https://reference.insulators.info/publications/view/?id=3469&h0=kern&h1=river