I was going to use Mammmoth as one of my safety airports today, but
found out it was closed for resurfacing! The NOTAM states

MMH 05/005 MMH AD CLSD EXC HEL ON PRKG APRON TIL 0809150700

So those soaring near Mammoth airport (at the base of the Sierra
Nevada Mountains in California for the rest of the group) be advised.

Martin
WT