Path 15

Most of the three AC 500 kV lines were built by Pacific Gas and Electric (PG&E) south of Tesla substation.

The third line between Los Banos and Gates substation, south of Tracy, is operated by the Western Area Power Administration (WAPA), a division of the United States Department of Energy.

The other line continues southwest for some distance and then turns south and enters the Vaca-Dixon Substation along Interstate 505.

[7] Just north of the Sacramento River and the city of Antioch the two lines rejoin and head in a south-southeasterly direction.

[3][4] Leaving the Tesla Substation (37°42′33.52″N 121°33′48″W / 37.7093111°N 121.56333°W / 37.7093111; -121.56333) one PG&E line heads southwest and two parallel PG&E lines continue in a south-southeasterly direction along the eastern foothills of the Diablo Range and the western edge of the San Joaquin Valley.

Despite being located in the eastern foothills of the Diablo Range, the two eastern lines cross a body of water - the O'Neill Forebay of the massive San Luis Reservoir (just to the east of the San Luis Dam) on several artificial islands.

[3][4] The lone southwestward 500 kV PG&E line crosses the Diablo Ridge, rising to 808 m (2,650 feet) near Mount Hamilton.

After crossing some rugged coastal hills, the line enters the Diablo Canyon Power Plant substation.

These parallel lines cross Highway 101 north of Pismo Beach and traverse over some southern coastal mountains.

After reaching a height of over 1,200 m or 3,937 feet,[8] the two parallel lines head down the arid foothills of the southern San Joaquin Valley and split up.

Southern California Edison's (SCE) two Path 26 lines connect to PG&E's grid at the Midway Substation.

[3][4] From north to south: WAPA's 500 kV line starts at the Captain Jack substation (42°4′38.06″N 121°23′25.47″W / 42.0772389°N 121.3904083°W / 42.0772389; -121.3904083) well to the northeast of Round Mountain.

It also heads southwest across the Modoc Plateau and crosses Interstate 5 near Cottonwood (north of Red Bluff).

This is the end of Path 66, but WAPA's 500 kV line continues from Olinda Substation along the western edge of the Sacramento Valley.

[3] The northern part of this electrical transmission corridor (including Path 66) is visible from space and Google Earth as lines of bare, treeless ground.

This entire project was built in the 1970s and 1980s in order to provide California and the Southwest with excess hydropower from the Pacific Northwest without actually having to construct any new power plants.

This transfer reverses in the hot, dry summers, when many people in the South run air conditioners.

[13] California's governor, Arnold Schwarzenegger attended the commissioning ceremony at California-ISO's control center in Folsom.

Path 15 near Winters
PG&E 500 kV line about to cross Interstate 80 as it leaves the Vaca-Dixon substation located just north of I-80 near Vacaville . The 230 kV line (smaller tower to the right) crosses I-80 as well after leaving the substation. This section of the transmission line between the Table Mountain Substation (near Oroville ) and the Tesla Substation (near Tracy ) is one of the two PG&E 500 kV lines. The lines often run together (see below map), but in this area they are split apart. The other 500 kV line crosses I-80 east of Davis .
Path 15 across O'Neill Forebay
Path 15 can be seen on the left of this map, south of San Francisco
A silhouette of Path 15 with C/2020 F3 (NEOWISE) in the night sky. This image was taken near the Little Panoche Reservoir along County Route J1 in western Fresno County.
The Los Banos substation.
Rare dual-circuit 500 kV tower (right) (operated by WAPA) and smaller dual-circuit 230 kV tower (left) (operated by Modesto Irrigation District), crossing I-580 .
2006 study proposing the 84-mile long, 500 kV line between Los Banos and Gates, which was eventually built. In the above illustration from 2006, only two of the eventual three lines are shown.