The march is set to start at 11:00 a.m. local time (19:00 GMT) and last for three hours.
“Bring your sidearms. Bring your long guns. This is a peaceful rally. But it is an armed one,” the group said on Facebook.
The rally has been organized to show support for activist Anthony Bosworth who on February 25, was arrested outside the Tom Foley Federal Courthouse in Spokane and detained for five hours.
“His only action was that he was standing outside the federal courthouse at a 10th amendment rally, while legally openly carrying a firearm,” the group said, adding that the police still have not returned Bosworth’s AK-47 rifle and 9mm sidearm.
US District Attorney for Eastern Washington Mike Ormsby said Thursday that Bosworth was arrested for failing to comply with the directions of federal police officers.
According to the local newspaper The Spokesman-Review, the Spokane protest rally will be joined by gun activists “from across the nation.” The Institute for Research & Education on Human Rights said Tea Partiers and other far-right activists will also take part in the march.
People in Washington, just like in most of the US states, are allowed to openly carry firearms without any license. However wide availability of guns frequently leads to tragedies, in particular when children get access to weapons. Last Sunday a four-year-old Texas boy accidentally shot and killed himself after finding a loaded gun in his babysitter's house and on Monday, a three-year-old boy in Tennessee shot his 18-month-old brother.