The Grateful Dead won't play their recently announced 50th anniversary reunion shows until July, but the ticket pre-sales are already giving the U.S. Postal Service a major workout.

According to the Dead 50 site, the first round of orders for the shows opened on Jan. 20, and it's already received an overwhelming response. "Wow! We’re excited (and humbled) to discover that your enthusiasm for Fare Thee Well matches our own! We have received an overwhelming number of mail order ticket requests," reads a note under "Ticket Info." "In an effort to honor the history and spirit of the Grateful Dead, we are going to try to fill as many of these orders as possible. This means there will be no other pre-sales."

Plans now call for the shows to go on sale to the public on Feb. 28 through Ticketmaster, but don't be surprised if they end up being awfully hard to come by -- Jambase notes that the band currently estimates more than 350,000 ticket requests across their scheduled three-show stand at Chicago's Soldier Field.

The response is impressive, but not surprising -- the Dead have always been a steady live draw, and these shows are also being billed as the band's farewell. As bassist Phil Lesh put it when they were announced, "It is with respect and gratitude that we reconvene the Dead one last time to celebrate -- not merely the band’s legacy, but also the community that we’ve been playing to, and with, for 50 years."

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