The mountains form a natural barrier between the Inland Empire region to the east and the job centers of Orange County to the west.
Only one freeway, the Riverside Freeway (State Route 91)  and the two-lane Ortega Highway (State Route 74) connect the regions.
Highway 91, which follows the Santa Ana River through a pass between the Santa Ana Mountains on the south and the Chino Hills on the north, is one of California's most congested routes.
Because of this, several proposals have been floated to excavate a highway tunnel through the Santa Ana Mountains, although the multibillion-dollar idea has drawn criticism from environmentalists and others concerned about cost and safety in the earthquake-prone region.
While Highway 91 is one of the most congested routes in California, Highway 74 holds a more ominous claim as one of the most dangerous highways in the state.
The mountains form a natural barrier between the Inland Empire region to the east and the job centers of Orange County to the west. Only one freeway, the Riverside Freeway (State Route 91)  and the two-lane Ortega Highway (State Route 74) connect the regions. Highway 91, which follows the Santa Ana River through a pass between the Santa Ana Mountains on the south and the Chino Hills on the north, is one of California's most congested routes. Because of this, several proposals have been floated to excavate a highway tunnel through the Santa Ana Mountains, although the multibillion-dollar idea has drawn criticism from environmentalists and others concerned about cost and safety in the earthquake-prone region. While Highway 91 is one of the most congested routes in California, Highway 74 holds a more ominous claim as one of the most dangerous highways in the state.
Santa Ana Mountains