Since 1863, six days a week, rain or shine- letters, bills, government checks, newspapers, even movies have arrived Monday through Saturday.
But the Postal Service said they aren't surviving, and it's an urgent situation.
"We cannot put our head in the sand and say well geez, lets hope this problem goes away" said Postmaster General Patrick Donahoe. "Hope is not a strategy."
Donahoe announced Wednesday steps to save money, by ending Saturday mail delivery.
So NBC Montana went to the Downtown Bozeman Post Office and talked with folks as they sent off letters and packages.
One resident and small business owner Jack Day said he supports the decision, and wouldn't have a problem adjusting.
"I think I can do very well without the Saturday delivery" he said."I think we can make it work."
But others don't understand why it has to go.
"I think it'll just be an additional hassle for people" said Big Sky resident Megan Keenan.
Keenan has a PO box in Big Sky. "I know it takes a while for it to get up to Big Sky anyway" she said, about the delivery.
And if Saturday delivery is nixed, she worries it'll push back mail arrival even more.
But we did some checking and found only businesses and homes won't receive Saturday mail. PO boxes are safe.
Under the new decision, packages of all sizes would still be delivered on Saturday, including medicines. Post offices would remain open.
The Postal Service hopes the cuts will help it save some $2 billion annually, after losing nearly $16 billion last year.
Residents like Day said Postal Service should do what it has to.
"I think we have to save money in the Postal Service somehow, and this is one way of doing it" he said.
Technically, the USPS still needs to get congressional approval before it can move forward with the plan.
But congress has failed to act in the past. So Postmaster General Donahoe is hoping a loophole might allow him to act on his own.
Officials want to start the new schedule August fifth.