I can’t believe I didn’t think of this book earlier. The Ring of Winter is from the 90s and is set in the Forgotten Realms jungle land of Chult. There are still dinosaurs alive there and the book has many conflicts between an Indiana Jones style character and dinosaurs. Definitely has a bit of Arthur Conan “The Lost World” feel to it. So it might be set a bit too far in the past for laser pistol cowboys, but hey, it’s still proving to be an interesting read. It’s part of the Harper’s Series (16 books in total, this was #5). The Harper’s are basically meddling, annoying Jedi style folks and the books centered around their exploits. I also used to love Soldiers of Ice (#7) from the series when I was a kid. But yeah I dug up my old copy of The Ring of Winter and am reading it in a totally new light now!