your best bet would be to fly in to Ontario, since LAX is super far away. Once at Ontario there are two alternatives. You can take the Super Shuttle to Big Bear directly, but I heard that's pricey. Or, you can take the Super Shuttle or any other form of transportation to the Metrolink station. Then take the metrolink all the way into San Bernardino Station. Once there, there ask the guard where the "MARTA" bus stops. The MARTA will take you up the mountain for $5 and will drop you off in the Vons parking lot. From there, you can take another MARTA bus to Bear.