In 1995, Terry Tempest Williams, in collaboration with Stephen Trimble, compiled Testimony: Writers Speak on Behalf of Utah Wilderness. This anthology showcased the voices of twenty writers advocating for the protection of 1.9 million acres of southern Utah land. The book aimed to influence policymakers, similar to Williams' previous efforts with This Is Dinosaur, and was distributed widely, including to members of Congress.

During the dedication of the Grand Staircase–Escalante National Monument on September 18, 1996, President Bill Clinton praised the book, stating, "This made a difference." The publication played a role in the effort to secure wilderness protection, contributing to the creation of the monument and highlighting the importance of written advocacy for environmental preservation.