After leaving the Army he became professor of geology at the Illinois Wesleyan University. He also lectured at Illinois Normal University. Powell helped found the Illinois Museum of Natural History.

That restless nature again stirred, however, and despite having only one arm, Powell headed west to renew his explorations. In 1867 he led a series of expeditions into the Rocky Mountains and around the Green and Colorado rivers.

Powell then decided to undertake the trip down the Colorado into the Grand Canyon in 1869. He gathered nine men, four boats and food for 10 months and set out from Wyoming.

Passing through dangerous rapids, the group passed down the Green River to its confluence with the Colorado River (then also known as the Grand River upriver from the junction), near present-day Moab, Utah.

The expedition's route traveled through the Utah canyons of the Colorado River, which Powell described in his published diary as having "Wonderful features-carved walls, royal arches, glens, alcove gulches, mounds and monuments. From which of these features shall we select a name? We decide to call it Glen Canyon."

Powell's expedition had its defectors, but a core group made it to the Virgin River, which now runs under Lake Mead. Powell confirmed his theories about a Grand Canyon, which to that point had not been adequately explored.

Powell developed a love for the Canyon area. He wrote: "The Grand Canyon is a land of song. Mountains of music swell in the rivers, hills of music billow in the creeks and meadows of music murmur in the rills that ripple over the rocks. Altogether it is a symphony of multitudinous melodies. All this is the music of waters."

It wasn't enough; Powell made yet another expedition down river into the Canyon in 1871-72. This time the party included a surveyor, Professor Almon H. Thompson, Powell's brother-in-law, and an experienced photographer, E. O. Beaman, who, together with his successors, James Fennemore and J. K. Hillers, dramatically documented the river voyage.

Powell rode in the lead, perched in a chair lashed amidships where he commanded an unrestricted view of the way ahead and could signal to the other boats. The expedition was planned to last about a year and a half. During the first 4 1/2 months the expedition traveled from Green River Station to the mouth of the Paria River at the foot of Glen Canyon.

Thompson was largely responsible for conducting the exploration of the river. Powell spent most of July and August traveling on horseback between the river and Salt Lake City, exploring the canyon lands, and studying the Indian tribes.

The second expedition brought back considerable information. Professor Thompson completed a topographic map of the Grand Canyon region, and Powell's monumental account was published in 1875 by the Smithsonian Institution.

After this second expedition, Powell continued to study the Colorado River region under Government auspices. In 1878, encouraged by Secretary of the Interior Carl Schurz, he completed his report on the lands of the arid region of the United States, which was published as a Congressional document. The book, since recognized as one of the most important ever written about the western lands, went unheeded at the time.

Powell's research on the Indians and their cultures ultimately led to the creation of the Bureau of Ethnology. Powell became its Director, a post he held for the rest of his life.

In 1881, Powell was appointed Director of the U.S. Geological Survey. As Director from 1881 to 1894, Powell was the principal force in expanding geologic studies and topographic mapping throughout the country and in stimulating investigations of soil, ground water, rivers, flood control, and irrigation.

Powell died in 1902. Though honored and respected by the scientific community, Powell was for many years overlooked by historians. Only later did the significance of his ideas become rediscovered. Lake Powell is named after him.

While Powell made most of his reputation in the West, his Wisconsin years played a role in his interest in nature and development as an explorer.