According to the website for the shuttle service, its running starting 15 May. Its running at a lower capacity of passengers but more vans are added as needed. It runs on a schedule from 15 May to some date in the fall and then runs only on a will call basis. On the GrCa NPS website there is a link to the shuttle page. Check that out. There is a phone number there you can call as well.
Found Myself Outside