Since I'm spending more and more time in Idaho I decided to do some due diligence and bone up on the local laws RE OC/CC.

First I found and studied the state's preemption statute:

TITLE 18
CRIMES AND PUNISHMENTS
CHAPTER 33
FIREARMS, EXPLOSIVES AND OTHER DEADLY WEAPONS
18-3302J.Preemption of firearms regulation. (1) The legislature finds that uniform laws regulating firearms are necessary to protect the individual citizenís right to bear arms guaranteed by amendment 2 of the United States Constitution and section 11, article I of the constitution of the state of Idaho. It is the legislatureís intent to wholly occupy the field of firearms regulation within this state.
(2) Except as expressly authorized by state statute, no county, city, agency, board or any other political subdivision of this state may adopt or enforce any law, rule, regulation, or ordinance which regulates in any manner the sale, acquisition, transfer, ownership, possession, transportation, carrying or storage of firearms or any element relating to firearms and components thereof, including ammunition.
(3) A county may adopt ordinances to regulate, restrict or prohibit the discharge of firearms within its boundaries. Ordinances adopted under this subsection may not apply to or affect:
(a) A person discharging a firearm in the lawful defense of person or persons or property;
(b) A person discharging a firearm in the course of lawful hunting;
(c) A landowner and guests of the landowner discharging a firearm, when the discharge will not endanger persons or property;
(d) A person lawfully discharging a firearm on a sport shooting range as defined in section 55-2604, Idaho Code; or
(e) A person discharging a firearm in the course of target shooting on public land if the discharge will not endanger persons or property.
(4) A city may adopt ordinances to regulate, restrict or prohibit the discharge of firearms within its boundaries. Ordinances adopted under this subsection may not apply to or affect:
(a) A person discharging a firearm in the lawful defense of person or persons or property; or
(b) A person lawfully discharging a firearm on a sport shooting range as defined in section 55-2604, Idaho Code.
(5) This section shall not be construed to affect:
(a) The authority of the department of fish and game to make rules or regulations concerning the management of any wildlife of this state, as set forth in section 36-104, Idaho Code;
(b) The authority of counties and cities to regulate the location and construction of sport shooting ranges, subject to the limitations contained in chapter 26, title 55, Idaho Code; and
(c) The authority of the board of regents of the university of Idaho, the boards of trustees of the state colleges and universities, the board of professional-technical education and the boards of trustees of each of the community colleges established under chapter 21, title 33, Idaho Code, to regulate in matters relating to firearms.
(6) The provisions of this section are hereby declared to be severable. And if any provision is declared invalid for any reason, such declaration shall not affect the validity of the remaining portions of this section.
Pretty straight forward and all encompassing... I like it.

Then I sought out the restrictions:

TITLE 18
CRIMES AND PUNISHMENTS
CHAPTER 33
FIREARMS, EXPLOSIVES AND OTHER DEADLY WEAPONS
18-3302B.Carrying concealed weapons under the influence of alcohol or drugs. It shall be unlawful for any person to carry a concealed weapon on or about his person when intoxicated or under the influence of an intoxicating drink or drug. Any violation of the provisions of this section shall be a misdemeanor.
UtI carry is bad ju-ju. Fair enough....but I notice that this law specifies CONCEALED carry. HHhmmm....

TITLE 18
CRIMES AND PUNISHMENTS
CHAPTER 33
FIREARMS, EXPLOSIVES AND OTHER DEADLY WEAPONS
18-3302C.Prohibited conduct. Any person obtaining a license under the provisions of section 18-3302, Idaho Code, shall not:
(1) Carry a concealed weapon in a courthouse, juvenile detention facility or jail, public or private school, except as provided in subsection (4)(f) of section 18-3302D, Idaho Code; or
(2) Provide information on the application for a permit to carry a concealed weapon knowing the same to be untrue. Any person violating the provisions of this section shall be guilty of a misdemeanor.
No courthouses, jails or private schools. Common proviso's, but again...specifically applied to CONCEALED carry (and even more specifically Licensees ), and PRIVATE schools...

TITLE 18
CRIMES AND PUNISHMENTS
CHAPTER 33
FIREARMS, EXPLOSIVES AND OTHER DEADLY WEAPONS
18-3302D.Possessing weapons or firearms on school property.
(1) (a) It shall be unlawful and is a misdemeanor for any person to possess a firearm or other deadly or dangerous weapon while on the property of a school or in those portions of any building, stadium or other structure on school grounds which, at the time of the violation, were being used for an activity sponsored by or through a school in this state or while riding school provided transportation.
(b) The provisions of this section regarding the possession of a firearm or other deadly or dangerous weapon on school property shall also apply to students of schools while attending or participating in any school sponsored activity, program or event regardless of location.
(2) Definitions. As used in this section:
(a) "Deadly or dangerous weapon" means any weapon as defined in 18 U.S.C. section 930;
(b) "Firearm" means any firearm as defined in 18 U.S.C. section 921;
(c) "Minor" means a person under the age of eighteen (18) years;
(d) "Possess" means to bring an object, or to cause it to be brought, onto the property of a public or private elementary or secondary school, or onto a vehicle being used for school provided transportation, or to exercise dominion and control over an object located anywhere on such property or vehicle. For purposes of subsection (1)(b) of this section, "possess" shall also mean to bring an object onto the site of a school sponsored activity, program or event, regardless of location, or to exercise dominion and control over an object located anywhere on such a site;
(e) "School" means a private or public elementary or secondary school.
(3) Right to search students or minors. For purposes of enforcing the provisions of this section, employees of a school district shall have the right to search all students or minors, including their belongings and lockers, that are reasonably believed to be in violation of the provisions of this section, or applicable school rule or district policy, regarding the possessing of a firearm or other deadly or dangerous weapon.
(4) The provisions of this section shall not apply to the following persons:
(a) A peace officer;
(b) A person who lawfully possesses a firearm or deadly or dangerous weapon as an appropriate part of a program, an event, activity or other circumstance approved by the board of trustees or governing board;
(c) A person or persons complying with the provisions of section 19-202A, Idaho Code;
(d) Any adult over eighteen (18) years of age and not enrolled in a public or private elementary or secondary school who has lawful possession of a firearm or other deadly or dangerous weapon, secured and locked in his vehicle in an unobtrusive, nonthreatening manner;
(e) A person who lawfully possesses a firearm or other deadly or dangerous weapon in a private vehicle while delivering minor children, students or school employees to and from school or a school activity;
(f) Notwithstanding the provisions of section 18-3302C, Idaho Code, a person or an employee of the school or school district who is authorized to carry a firearm with the permission of the board of trustees of the school district or the governing board.
(5) Penalties. Persons who are found guilty of violating the provisions of this section may be sentenced to a jail term of not more than one (1) year or fined an amount not in excess of one thousand dollars ($1,000) or both. If a violator is a student and under the age of eighteen (18) years, the court may place the violator on probation and suspend the juvenile detention or fine or both as long as the violator is enrolled in a program of study recognized by the court that, upon successful completion, will grant the violator a general equivalency diploma (GED) or a high school diploma or other educational program authorized by the court. Upon successful completion of the terms imposed by the court, the court shall discharge the offender from serving the remainder of the sentence. If the violator does not complete, is suspended from, or otherwise withdraws from the program of study imposed by the court, the court, upon receiving such information, shall order the violator to commence serving the sentence provided for in this section.
OK..Public schools covered for all modes of carry.

What I'm failing to find is ANY state legislation prohibiting (or allowing for a prohibition on) the OPEN carry of a personal sidearm into a courtroom (or jail or private school)