Cache Crater is located on Bureau of Land Management (BLM) lands. There is a short gravel trail leading to the cache site from an easily accessible parking area off Route 21 (about 6 miles north of Odessa, WA).
Unlike the nearby Amphitheatre Crater, Cache Crater is a deep circular depression in the basalt, and was likely formed by the "plucking" action of the catastrophic Missoula Floods over 10,000 years ago. But what geologists are still trying to figure out, is why this crater formed here in the first place. Was there a weakness in the structure of the basalt, or was something else at work?
Here's your chance to put on your GEO hat and do a little hypothesizing yourself. I'm sure the USGS and the rest of us would love to hear a fresh new explanation of the mystery craters out here!
Oh yeah, about the geocache... it's a nut jar full of all sorts of goodies. You shouldn't have any trouble locating it. Have fun and post your theories on how you think Cache Crater formed, and while you're at it, head out to the nearby Odessa Crater Trail Rock Exchange by Sharp88 to see a little more geology.