The story
The National Railroad Passenger Corporation (Amtrak) assumed operation of almost all intercity passenger rail in the United States in 1971. Service in California, as in most of the United States, was basic and infrequent. In 1976 California began providing financial assistance to Amtrak. Around 1990, the Caltrans Division of Rail was formed to oversee state-financed rail operations and the brand Amtrak California started appearing on state-supported routes. Prior to that, rail management and oversight at Caltrans was part of the Division of Mass Transportation. The two divisions have since been merged into the Division of Rail and Mass Transportation.
In 1990, California passed Propositions 108 and 116, providing $3 billion for transportation projects ($7.4 billion after inflation), with a large portion going to rail service. As a result, new locomotives and passenger cars were purchased by the state, and existing inter-city routes expanded. A more distinct image for Amtrak California, such as painting locomotives and passenger cars in "California Color" of blue and yellow, was established with the arrival of new rolling stock.
In 1998, while still funded by the state, the management of the Capitol Corridor was transferred to the Capitol Corridor Joint Powers Authority (CCJPA), formed by local jurisdictions of the line serves. In 2015, the management of the Gold Runner (then called the San Joaquins) and the Pacific Surfliner were similarly transferred to the San Joaquin Joint Powers Authority (SJJPA) and the Los Angeles-San Diego-San Luis Obispo Rail Corridor Agency (LOSSAN Corridor JPA), respectively. As a result, the Amtrak California brand became less prominent in the websites and marketing materials. Caltrans still has a role in reviewing annual business plans submitted by the three JPA's.
As of 2022, Caltrans is studying Amtrak service to the Coachella Valley.
From Wikipedia’s article on Amtrak California, shared under CC BY-SA 4.0.4