Something Wilder question

I am currently reading this book and I have come to a part that makes no sense and I'm wondering if anyone can help me figure it out. SPOILER ALERT: DO NOT READ ANY FURTHER IF YOU PLAN ON READING THIS BOOK!!
So, after Terry dies, the group decides to continue on looking for Duke's treasure. It talks about them riding their horses, which are loaded with their camping gear, to a small town. When they arrive, they go into a bar where Duke used to hang out. The next thing you know, the gang has hurriedly left the bar and they are riding in a Jeep and being chased by two men in a truck!! So, where did the Jeep come from? Did they steal it? There is no mention of that. What happened to the horses? Did they leave them behind in the little town? So, a few paragraphs later, it talks about them arriving at their campsite for the night and about them setting up their tents. Just a few pages earlier, all their gear camping gear was on the horses. How did the camping gear get from the horses to the Jeep? I even went back and reread it but I still can't figure out this mystery. Can anyone help me?