A 70’s chapter book. Some children are staying in the Southwest US, or maybe California (I think) on a ranch (?) find an old diary/clue from a doomed explorer saying “gold in here”, meaning in a cave or underground cavern. Turns out be “cold” when the mystery is solved.
It’s Clyde Robert Bulla’s _Ghost Town Treasure_. Google returns a similar search with the result in the Loganberry archives.
The Linda Craig series by “Ann Sheldon” springs to mind.
Pretty certain this is “Ghost Town Treasure”, by Clyde Robert Bulla. Ty and his parents live in the abandoned town of Gold Rock, but they are planning to close their grocery store and leave, to Ty’s dismay. His pen-pals Nora and Paul come visit, with their grandfather’s diary, hoping to look for gold in an abandoned cave. You’re correct about the “gold/cold” part; ultimately there’s no treasure but the intrigue of the newly-discovered cave does revive the lonely town. Hope this helps.
Hi, I am the original poster, and yes, this is definitely solved! That was fast! I am so glad that others remember this book at all and that it inspires some fond memories from other readers. The current cover is different, but the details sound right. That “cold/gold” mix-up is very specific. I don’t imagine there are any other books that would have that plot line. Thank you very much to those who answered. This was one of the last few books I have left to search for, from my childhood reading.