Warren Cook, age 10, is thin and tan and there are dark circles around his eyes, because for the past two days he has been running.

Cook, who lives with his family in Sandy, ran 20 miles across Utah's west desert as a participant in the Snake Valley Citizens Alliance's Water Express Run. The 223-mile run culminated Wednesday at a demonstration at the Wallace F. Bennett Federal Building in Salt Lake City, and Cook was there.

When asked why he ran so far, what was so important, Cook squared his shoulders and stood up.

"My mom and her family, they have a ranch in Juab County," he said, kicking at the dust that still covered his shoes. "Las Vegas is stealing our aquifers, and I just wanted to support her, and let the government know what they're doing. Because it seems like it isn't really doing anything."

Cook, along with about 50 other demonstrators, protested a proposal being explored by the Southern Nevada Water Authority that would divert water from rural eastern Nevada and parts of western Utah to serve the rapidly growing Las Vegas area.

The water authority claims it needs to at least study the option because Las Vegas is booming, and, in spite of conservation efforts, the area will need more water. And, it says, there is evidence indicating that the Snake Valley — which includes ranching towns like Callao and Garrison — contains some surplus water in underground aquifers.

But members of the Snake Valley Citizens Alliance disagree, claiming that the water authority's plan will devastate the area — its economy, its heritage and the environment.

On Wednesday, members of the alliance delivered bundles of letters, T-shirts and samples of Snake Valley spring water to local officials: the Utah congressional delegation, Gov. Jon M. Huntsman Jr. and officials in Millard, Juab and Tooele counties.

"We have gone through eight excruciating years of drought," said Callao rancher Cecil Garland. "The vegetation shows it. The water table shows it. Our whole ecosystem has suffered, and I will say this again: We have no surplus water in Snake Valley.

"The taking of water is the destruction of habitat," Garland said. "And the destruction of habitat is a subtle form of genocide."

All but Huntsman and Rep. Jim Matheson, D-Utah, dispatched representatives to the demonstration.

"The senator is very concerned, and he wants to work with (Utah) state officials on the issue to see what he can do to help," said Heather Barney, spokeswoman for Sen. Orrin Hatch, R-Utah. "He knows that this is an issue of extreme importance to citizens of this area and will do everything he can to help them."