Boomboy, hopefully if you are driving you are taking the 'northern' route and avoiding WY, NE, CO, MN, & IL since those states do not honour the Evergreen's privilege card. [
https://handgunlaw.us/states/washington.pdf ]
Additionally, per handgunlaw - iowa, there is no duty to immediately notify LE upon contact per Iowa statute, quote:
724.5 Availability of permit not to be construed as prohibition on unlicensed carrying of weapons. The availability of a professional or nonprofessional permit to carry weapons under this chapter shall not be construed to impose a general prohibition on the otherwise lawful unlicensed carrying or transport, whether openly or concealed, of a dangerous weapon, including a loaded firearm.
[
https://www.legis.iowa.gov/docs/code/2022/724.5.pdf ]
Twasn't clear from "...traveling through Iowa..." if that was your final destination per se., but safe travels...weather permitting...