Service is primarily to the greater Monterey and Salinas areas, but extends as far south as Paso Robles and as far north as Watsonville and Gilroy.

The Monterey and Pacific Grove Railway provided the first intra-county services using horse cars starting on August 5, 1891.

[3]: II-1, A-7, A-8 The first motorbus services began in 1918, provided by the Monterey-Carmel Bus Line; a younger upstart, Bay Rapid Transit, was formed in 1922.

[3]: II-1  Bay Rapid Transit aggressively challenged existing streetcar lines, operating over the same routes and offering promotions and lower fares to attract passengers.

The facilities of the Monterey and Pacific Grove Railway were destroyed in a mysterious fire and that streetcar line ceased operations in December 1923.

[3]: A-9 By 1972, it was apparent that Bay Rapid Transit, like other privately-owned transportation services in California, would need public subsidies to continue operations.

[11] MST performs maintenance and refueling at four facilities:[7]: 15 Media related to Monterey–Salinas Transit at Wikimedia Commons