Welcome From Montana....

We are retired rangers from Yellowstone NP and recently purchased a 550 teardrop. What is a good vender for the purchase of a portable solar panel?

 

Look at Renogy. I bought a 100 watt solar suitcase model without a controller on sale for $175. I’m not sure if the sale price is still valid.

 

Welcome to the forum!

With all the different camping equipment you've no doubt seen through the years at Yellowstone, it's nice to see that you chose the Camp-Inn for your retirement camping!!

There are solar panels available in a number of different styles (flexible, rigid, framed, frame-less, mono-, or poly-crystalline, etc), and sizes.
If you do a search on the forums search engine, you will find quite a bit of info on a number of those types, and some info on vendors that members purchased their solar supplies from as well. Also different ways of hooking them up to the electrical system as well, depending on whether it's for a stand alone battery or the CI battery, whether your more of a DIYer, or prefer something that is more plug n play.
It's a bit of a subjective question, as are the answers in the forum, but in the end using the search results may help you see some of the options available, and help you make a better informed decision.

Good luck with your solar decision, and enjoy your retirement camping in your Camp-Inn!