(Photo courtesy of Thunderbird Foundation for the Arts) "Woman Grinding, Kaibab Plateau," an image created by photographer Jack Hillers during explorer John Wesley Powell's a second expedition, between 1872 and 1875.

A century-and-a-half ago, as the transcontinental railroad was completed in northern Utah, another momentous journey was underway in southern Utah.

On May 24, 1869 — two weeks after the Union Pacific and Central Pacific railroads met at Promontory Summit — John Wesley Powell set out from Green River, Wyo. His journey would take him and his party down the Green River to the Colorado River, near Moab. He and his party continued through Utah canyons and on to Arizona, where his was the first U.S. government-sponsored passage through the Grand Canyon.

The Thunderbird Foundation for the Arts in Mount Carmel is celebrating the sesquicentennial of that Powell expedition with an art show and a book that focus not just on the explorer, but on the American Indians he encountered on his journey.

Artist Robert Goldman will showcase a series of 37 paintings celebrating locations where Powell traveled in 1869. And the Thunderbird Foundation has published the book, “The People: The Missing Piece of John Wesley Powell’s Expeditions,” which celebrates the contributions of the Southern Paiute tribes to Powell’s expeditions.

Carol Ormond’s book includes 116 of photographer John Hillers’ original 1872 albumen photographs of the Southern Paiute, which are only available for viewing at the Smithsonian in Washington, D.C. and at the Maynard Dixon Museum in Mount Carmel.

(Powell retraced part of his 1869 trek in 1871-72.)

“While both Powell and Hillers have been celebrated, the Indians who contributed to their successes have been largely unknown and unrecognized,” said Paul Bingham, executive director of the Thunderbird Foundation. “Through this book we hope to honor the Paiutes who helped Powell, and their descendants who live among us today.”

(Photo courtesy of Thunderbird Foundation for the Arts) John Wesley Powell and Taw-Gu, Great Chief of the Paiutes, in an image created by photographer Jack Hillers during Powell's second expedition, between 1872 and 1875.

The Thunderbird foundation partnered with Git ‘er Done Books to publish the book, which also includes photos of Utes, Navajos and Hopis. It’s available for purchase at thunderbirdfoundation.com.

These events are all scheduled for Saturday, May 18.

Exhibit launches • The exhibit will open to the public at 11 a.m. at the Maynard Dixon Home and Studio, 2200 State Street, Mount Carmel. It’s scheduled to continue through Dec. 31.

Robert Goldman lecture • Goldman will speak at 11 a.m. at the Old Rock Church, 10 S. Main St. Providence.

Carol Ormond symposium/book signing • Ormond will appear as part of a panel discussion, and will sign copies of her book at 1 p.m. at the Old Rock Church.

Private reception • Admission is free but RSVPs are required at thunderbirdfoundation.com. The reception — 6 p.m. to 9 p.m. at the Maynard Dixon Home and Studio — will be the grand opening for both the photo exhibit and “A New Perspective,” the collection of 37 Goldman paintings.