Wyoming passed on hosting the Rocky Mountain Regional last year. An unofficial regional was hosted by the MadRats in Colorado last Labor Day but no business meeting was held during it, so no state officially accepted this year's event.
The Utah Grottos voted to host this year's regional but this note was posted today on the Colorado Caves and Caving Forum:
Because of the lack of response from Utah cavers to actively support the 2007 Rocky Mountain Regional at Kane Hollow, those individuals charged with finding help for the various chores decided to throw in the towel. There will be no RMR this year unless some other state decides to give it ago.