Tribes in the southwest hold significant rights to the Colorado River’s water. But they’ve been left out of nearly every major agreement to manage the river. Leaders across the region are debating how to use less water amid the region’s warming climate. Tribes say they never got the chance to use their water in the first place, and that everyone in the river basin should plan for a future where they do.

Las Vegas is known as a city of excess. But not when it comes to water. The desert metropolis relies on the Colorado River to keep its iconic casinos bustling. The short supply has caused city leaders to enforce some of the tightest water conservation measures in the West. Green lawns are enemy number one.

The Colorado River’s current crisis traces its roots back to 1922. That’s when leaders from the rapidly-growing southwestern states that rely on the river traveled to a swanky Santa Fe mountain retreat to divvy up the river’s water. Growing populations in some of the West’s burgeoning cities and sprawling farmlands, and the anxieties tied to that growth, pushed leaders to the negotiating table.