The Department of Public Safety gets to decide what states' permits are acceptable. At this time, Missouri is not on the list:
Idaho "Enhanced" Permit*
North Dakota "Class 1" Permit*
As for carry while you visit, feel free to read through our state laws starting at NRS 202.253 at this link: http://www.leg.state.nv.us/NRS/NRS-202.html
Briefly, State Law is preempted to trump all local and county laws regarding carry and possession. OC is legal (as no law prohibits or mentionsthe activity). Concealed carry is a felony without a valid permit, but concealed carry is defined as "a loaded or unloaded handgun which is carried upon a person in such a manner as not to be discernible by ordinary observation (NRS 202.3653)." So, in simple speak, if we can see your gun, it isn't concealed on your person, ergo OC. Generally, a loaded handgun in the car, under your seat, on your hip, in your glove box, etc, is all perfectly legal. Hope you enjoy your trip!