Gun rights activists are cheering a federal court ruling in Colorado that declared unconstitutional a US Postal Service (USPS) regulation that bans firearms in post office parking lots.

The case was brought by the Colorado-based National Association for Gun Rights (NAGR) and a citizen named Tab Bonidy, who has a concealed carry license in the Centennial State. They were represented by the Mountain States Legal Foundation (MSLF), which filed the lawsuit in October 2010.

The case revolved around Bonidy’s argument that he must pick up his mail at the post office in Avon, CO because there is no mail delivery at his rural home. Since he frequently carries a handgun for personal protection, the regulation prohibiting his gun on post office grounds constituted an undue burden on his exercise of the Second Amendment right to keep and bear arms.

In July 2010, Bonidy asked the postal service to withdraw the regulation, according to the MSLF press release, and when the USPS refused, he pursued the legal action.

The regulation has been in effect for more than four decades, and was renewed most recently in 2007. Under the restriction, no person may carry or store firearms or other so-called “dangerous or deadly weapons” on USPS property. Violations carry fines and jail time.

MSLF noted in a press release that the USPS ban “impairs the right to keep and bear arms as protected by the Second Amendment even when individuals are traveling to, from, or through Postal property because the Postal Service does not allow people to store a firearm safely in their vehicles.”

“Anyone with a hunting rifle or shotgun in his car, or a handgun in his glove compartment for self-defense, violates the Postal Service ban by driving onto Postal Service property,” MSLF said. “Thus, the ban also denies the right to keep and bear arms everywhere a law-abiding gun owner travels before and after visiting Postal Service property.”