Walk-in permits for Bishop Pass at Bishop's White Mtn. ranger station (on Main St, Bishop, CA) can be obtained quite easily Monday to Thursday. The process is as follows:
Apply for the permit on the morning of the day before you want to cross Bishop Pass. Get there early (8 AM)! Go for breakfast. Then, at about 11 AM that day (the computer system won't let them issue permits until then), the rangers begin issuing the walk-in permits for the next day. As a Bishop resident, I use this system throughout the Summer, and always manage to get a permit. There are usually fewer walk-in permits available for Saturdays and Sundays.
By June, the parking lot at the Bishop Pass trailhead begins to fill quickly, so again, get there early.
For exits other than Whitney, you might try for Kearsarge Pass, which is a fairly moderate walk-out. Then hitch a ride down to Independence from the Onion Valley trail-head. Lots of people use that trailhead; you probably won't have to wait long for a lift out.
Last edited by Bob West; 04/25/16 07:38 AM.