The Idaho State Constitution, Article 1, Section 11 reads as follows:
"RIGHT TO KEEP AND BEAR ARMS. The people have the right to keep and bear arms, which right shall not be abridged; but this provision shall not prevent the passage of laws to govern the carrying of weapons concealed on the person nor prevent passage of legislation providing minimum sentences for crimes committed while in possession of a firearm, nor prevent the passage of legislation providing penalties for the possession of firearms by a convicted felon, nor prevent the passage of any legislation punishing the use of a firearm. No law shall impose licensure, registration or special taxation on the ownership or possession of firearms or ammunition. Nor shall any law permit the confiscation of firearms, except those actually used in the commission of a felony."
The astute reader will notice that first, the state may not pass laws regulating the *open carry* of weapons, and second, that a firearm may not be confiscated or seized unless it was used in the commission of a felony. Ergo, it is completely legal to walk down the streets of Boise with an AR strapped to your back!