"From our perspective the most important thing is now the state is going to have to be consulted on for any development that happens within the flat-tailed horned lizard habitat," she said.

There is dispute over whether the species is in fact declining, and how many live in the dunes. A biologist with the Bureau of Land Management, Larry LePre, told the Yuma Sun in December the dunes aren't prime habitat since they don't have many of the harvester ants which are the basis of the lizards' diet, and there's no reliable data to suggest they're going up or down in numbers, mostly because they're difficult to detect.

The BLM, which maintains the Imperial Sand Dunes Recreation Area, is part of a joint Rangewide Management Strategy for the species covering almost 500 acres in California and Arizona. The center's petition contends this is inadequate since most of the land is open to off-road vehicle use.