We finished building our new house in December, and moved right in. Now that it's Spring around here, we're diving into putting in our yard and landscaping. I'm a life-long low-level pyro, I love me a good campfire. I think it ties back to having some extremely fond memories of loved ones and camping/campfires with them.

Long story short, we're going to have a fire pit at our house, 100%. As we've been doing some grading and prep work for putting in some landscaping and lawn, I've found we have a high concentration of what most people call "river rock" in our soil, and the rocks range in size from pebbles to about the size of bowling balls. We live in Idaho, in an ancient river plain (the Snake River Plain), so for the past veeeery long while, all this "river rock" has not been in a "river", it's been in dirt, and the climate here is generally semi-arid. The water table here is a good ways down, I think around/at least 100 feet down, maybe more. Our particular neighborhood had been cattle farm/grazing grounds in recent decades, but hadn't had cattle for a little while before they developed it. Seeing as this "river rock" isn't coming out of a river, is it safe to use in a fire pit? I know the reasoning behind not using actual rocks from rivers in fire pits, and how they can and do explode from internal moisture trying to expand and turn into water vapor and all that. I guess my question is, does this happen with "river rock" that hasn't been in a river for hundreds or thousands of years? Or is it a hard and fast rule, where you just plain do not use that kind of rock, period, because it likely has too much moisture in it?

Has anyone ever done any fire pits with river rock, with or without mortar, and had it be totally fine and safe, due to a certain reason/rule that makes it safe? Or, has anyone here done any other landscaping with their river rock? We have so much that I'm trying to come up with ideas of how to use it. Maybe rock and mortar garden beds or planters? Maybe a fake well? I don't know. Thoughts?