The letter cited a USPS statistic that 90 percent of post offices are within 10 miles of another, and therefore may be closed. But the Oregon Democrats said this is less true in Oregon.

"While this may be true nationwide, we were alarmed to see that of the 41 post offices in Oregon on the list for possible closure, over half of them are more than 10 miles from the nearest post office," they wrote. "Expecting a customer to drive an hour round-trip to visit the nearest post office is unreasonable and does not align with the Postal Service's mission to 'provide prompt, reliable and efficient services to patrons in all areas and shall render postal services to all communities.' "

The members also argued that closing post offices in many small towns would destroy the identify of these towns.

"In many communities, post offices are a central part of the town," they wrote. "Some have been in existence for over a hundred years and in some towns the post office is one of only a few retail shops. Having a post office is central to a town's identity and the decision to close post offices should not be taken lightly."

Oregon's only Republican, Rep. Greg Walden, was not a signatory to the letter. The sixth seat from Oregon is vacant due to the resignation last week of Rep. David Wu (D).