Mailbox Peak is considered one of the toughest climbs along the I-90 corridor in the Cascade Mountains. At the summit there is a mailbox - assuming that hasn't gone missing again - and muggles and cachers alike treat it much the same as a geocache - signing the log, sharing thoughts, and even trading items - but you're looking for a regular cache near the summit.
This replaces a cache that had gone missing and was right on the summit but fairly exposed. This new cache is nearby and will hopefully be protected from muggles visiting the summit. Please be sure to hide it as well or better than you found it and this cache should be around for a while.
In nice weather, this summit attracts a lot of people so try to be inconspicuous as you approach the GZ.