Hello! I'm new to this site so sorry if my post is wonky.

This morning my boyfriend and I were out walking his dog when a little brown garter snake came right up onto his foot. I noticed the dog get sketched out (he didn't touch the snake at all, he was scared of him lol), looked down to see the snake, and pointed it out to my boyfriend. The snake then moved away by about 1ft and I figured I could catch it for a photo, then release it. I've worked with animals a ton both as a kid and as a camp counselor so I know how to grab/hold snakes safely but beyond that I really dont know much.

As I held this little friend, who is very sweet by the way, I noticed that near the end of his tail was a fairly large gash. Not so recent that it was still bleeding, but still pretty open and worrisome. I'll post a photo if I can figure out how. Not to mention we were on an overpass to a freeway. So after a quick discussion my boyfriend ran upstairs for a box and now we have him indoors and are hoping to treat him.

He's in a large box that is taped up around the corners for extra reinforcement, with holes in the lid, and dirt/a few plants to hide under. I had to run off to work but my boyfriend is home figuring out a water dish (we are thinking it should be small until his wound is more closed) and either a heating pad underneath or letting him bask in the sun (our house has a lot of windows). My mom has a 10gallon tank from when she first got her bearded dragon that she's going to give to me for him.

We read that he might like nightcrawlers for now.

What we really need to know is the best possible treatment for his injury if anyone can help! It looks like he maybe had a chunk bit out of him or maybe cut himself pretty bad trying to get somewhere? I'm guessing he's about 12 inches long and the gash is maybe three inches from the end of his tial, and about 3/4 of an inch wide

As a sidenote we do live in Oregon where the vets have been kind of overwhelmed recently treating animals from the fires, so while I may be able to take him in, it might be a long time. Any experiences or help is super appreciated, we want him to live.