Check this.

来源: 2013-04-05 18:58:51 [旧帖] [给我悄悄话] 本文已被阅读:

All Water available seasonally should be on by this time.
http://www.nps.gov/grca/planyourvisit/upload/BrightAngelTrail.pdf

For others:
http://www.nps.gov/grca/planyourvisit/brochures.htm