Apparently Idaho has the best reciprocity policy in the US:
Firearm Laws - Idaho.gov
Firearm Laws
* Statute 18-3302. Issuance of Licenses to Carry Concealed Weapons
Any person who has a valid permit from a state or local law enforcement agency or court authorizing him to carry a concealed weapon is authorized to carry a concealed weapon in Idaho...
Firearm Laws - Idaho.gov
Firearm Laws
* Statute 18-3302. Issuance of Licenses to Carry Concealed Weapons
Any person who has a valid permit from a state or local law enforcement agency or court authorizing him to carry a concealed weapon is authorized to carry a concealed weapon in Idaho...