Few things are as iconic in the American Southwest as the Colorado River. It is the sixth longest river in the country and flows through 11 national parks and monuments—including Grand Canyon National Park.

The Colorado River is sometimes called the hardest working river in the West as it is a critical water supply for agriculture, industry and people. It also supports recreational adventures—from fishing and whitewater rafting to hiking and wildlife viewing. The river supports the water needs of more than 36 million people across seven states and two nations!

So how did we discover the Colorado River and learn to rely on it? According to the National Park Service, Jedediah Smith led the first documented exploration of the Salt Lake region to the Colorado River in the 1820s. In 1869, John Wesley Powell led a team of explorers on the first thorough investigation of the Green and Colorado rivers. The team took a three-month trip down the Colorado River, traveling through Colorado, Arizona and Utah before stopping at what we now call Lake Mead in Nevada. Powell was the first explorer to complete a successful downstream river boat expedition—what a trip that must have been!

As more people began settling in the West, the Colorado River proved to be a valuable resource for those in the surrounding areas. In 1922, the Colorado River Water Compact was drafted to divide water from the river among the surrounding states. Hoover Dam was built between 1931 and 1936 to feed Lake Mead, generate electricity, and supply drinking water.

Unfortunately, overutilization and climate change are taking their toll on the Colorado. The river’s reservoirs continue dropping to new lows, and the federal government recently told the seven states that they need to quickly find ways of drastically cutting how much water they take from the river. While agriculture consumes the majority of the water that’s taken from the river, we can all do our part by reducing our water usage and being thoughtful every time we turn on the tap!