The narrowed pool of waters receiving federal protection under the rule could be severe for critical wetlands and streams in the arid West, many of which are seasonal or fed by groundwater.

Senators characterized the agency’s decision-making process as “rigid” and “slow,” and said they want states to have a bigger role.

At a conference of western governors in Arizona last week, the region's energy future dominated the conversion as populations and the AI data center industry continue to grow and drive up demand.

A new study in the Rocky Mountains has found a steep drop in the number of young American pikas — small, high-altitude mammals known for their distinctive squeaks and rock-pile homes. Researchers say the 50% decline could be an early sign of deeper ecological shifts as the climate warms.

Wyoming ranchers are testing GPS collars to help manage the movement of their livestock.