Welcome to the forum @John589.
We have had various threads about traveling and how to do it. In practice it varies from State to State, and even down to the local level in some places (Colorado). I check what laws I may run into well before I do the trip. As a backup, I have several containers that lock, and I have a ton of weapon locks.
At a minimum, if I am going to traverse a prohibited area (I typically won’t stop, even for fuel, if possible at all):
A locked container, containing the firearm, that is also breech locked (padlock through the port). That is two actions just to make a gun ready.
Magazines are in another locked container, empty.
Ammo is in another locked container.
They are all in separate areas.
While I will say I believe this is far over the top in most cases, I am not planning for most cases. Also, as I said above, I avoid places where I even need to do such things. I have not completely cut out Colorado, yet…