There were 9,142 applications submitted this year to the lottery. Dates are being awarded today, and people are charged automatically as the dates are awarded. The credit card charging process should be completed by the end of the day today.
People who entered an invalid CC number will be contacted starting March 26, so they won't even know whether they were successful until the phone call.
The available slots left will show up on Recreation.gov site sometime this weekend. Reservations with bad CC numbers that cannot be resolved will show up after March 26, as well. None of the slots remaining available can be reserved until April 1.
The April 1 scramble will start at 7 AM Pacific time. At that time computer users will have a few seconds to grab the slots they want (because lots of hikers will all be clicking at the same time). They set the time to 7 AM so people without a computer can phone Recreation.Gov and try for the same slots. (Guess who has an advantage.) It is likely the permits will all be "gone in 60 seconds."