From Los Angeles:

Take Interstate 10 east to the Highway 30/330 exit.
Take Hwy 30 north to 330, which turns into Highway 18 north.
Turn right at Big Bear Dam to the resort.

The distance is approximately 106 miles

From San Bernardino:

Take Interstate 10 east to the Hwy 30/330 exit.
Take Hwy 30 north to Hwy 330, which turns into Highway 18 north.
Turn right at Big Bear Dam to the reosrt.

The distance is approximately 46 miles

From San Diego:

Take Interstate 15 north to Interstate 215 north to Interstate 10 east.
Take Interstate 10 east to Highway 30/330 exit.
Take Hwy 30 north to Hwy 330 north which turns into Highway 18 north.
Turn right at Big Bear Dam to the resort.

The distance is approximately 155 miles