Looks as if the genetic sequencing projects may have some pretty good side effects.

But the LeSatzes aren't able to build their own riding arena. The only decent site on their property in southeastern Wyoming lies within 300 feet of Chugwater Creek, and building there is far too expensive because of Endangered Species Act restrictions intended to protect the Preble's meadow jumping mouse.

"The mouse that doesn't exist," Amy LeSatz noted drily.

After six years of regulations and restrictions that have cost builders, local governments and landowners on the western fringe of the Great Plains as much as $100 million by some estimates, new research suggests the Preble's mouse in fact never existed. It instead seems to be genetically identical to one of its cousins, the Bear Lodge meadow jumping mouse, which is considered common enough not to need protection.