The term you want to look up (and use at the border) is the Western Hemisphere Travel Initiative (WHTI).
In my experience at more land, air, and sea borders than I care to count, the most important thing if you are a "non-standard" traveler (e.g., aren't traveling with a full-fledged passport and/or the most common visa where required) is to know whatever government's own term for the program you are entering under. These are usually the magic words.
Here is CBP's WHTI site, which has tons of details and spells it out:
https://www.cbp.gov/travel/us-citizens/western-hemisphere-travel-initiative
So what you would say to the border guard is something like:
"I am a US Citizen re-entering the US using my Oregon EDL, as permitted under the Western Hemisphere Travel Initiative".
I've learned this lesson the hard way in countries much less friendly than the US of A, but it works pretty well when coming home too. Government bureaucrats are the same the world over, and throughout history
😀
(also, one thing that I have always found interesting about WHTI. If you're a US Citizen traveling by air from Canada, you have to present a passport unless you have a NEXUS card, but non-US-citizens can just present their green card, no passport required)