I have 4 credit cards with mileage.

1. Chase Signature Visa has some 79K. Never expire.
2. Citi Thank You has some 31K.
3. BA USAir Signature Visa has some 28K
4. BA Alaskan Airlines Signature Visa has some 32K.

Is there any way I can combine all these miles into one account? Transfer, etc?

Thanks.