Trail markers in the USA can vary greatly, depending on if the land is municipal, county, state, or federal, or even an unofficial but widely used trail. I’m only really familiar with ones in Alaska (where I am originally from) so I’m happy to try and find some examples of what you may come across if you get Alaskan trail markers. Gotta dig up some old pics and see if I happen to have anything/Google a bit to see what I can find to help.
Edit: Here’s a few examples of what you may find in Alaska.
An unofficial but widely used trail may have something like this:
(Credit to Christina Krause via all trails.com
State of Alaska owned/maintained trails look something like this, usually the signs are brown in color:
Photo by Brandon Cross
This is on property of the National Parks Service (Kenai Fjords National Park) I can’t guarantee that all of the other parks use the same kind of signs since I’m really only very familiar with this park, but signs like this are typical in my experience:
