Dr. Sarvis is a 50-year-old surgeon living in Albuquerque, New Mexico. Known for his bald head, beard, and constant cigar smoking, he harbors a deep resentment for the industrial pollution that causes respiratory illnesses in his patients. He uses his substantial income to fund the gang's environmental sabotage operations, buying their gear and explosives while insisting they avoid physical violence against people.

Bonnie is a 28-year-old former dancer from the Bronx who fell in love with the American Southwest during a college trip. She lives in a geodesic dome in Albuquerque and works as an office clerk, nurse-aide, and chauffeur for Dr. Sarvis. Outspoken and independent, she firmly pushes back against the sexist attitudes of her male co-conspirators while struggling with the boredom and anxiety of being relegated to the role of lookout.

Hayduke is a 25-year-old former Green Beret who spent 14 months as a prisoner of war in Vietnam. He returns to Arizona hoping to find solace in the desert, only to discover it overrun by bulldozers, power lines, and industrial smog. Short, broad, and deeply traumatized by his military service, he possesses a volatile temper and a strong preference for extreme, explosive sabotage over peaceful protest.

Smith is a 35-year-old polygamist and lapsed Mormon who operates a back-country guiding business. He maintains three separate households with his wives across the region. Deeply connected to the local geography, he mourns the damming of the Colorado River and the creation of Lake Powell, which flooded his hometown of Hite, driving his desire to destroy the Glen Canyon Dam.

Bishop Love is a Mormon bishop and prominent businessman heavily invested in real estate, tourism, and cattle in San Juan County. He leads the local Search and Rescue team, which frequently acts as a vigilante group aligned with the sheriff's department. He actively pursues the saboteurs to protect the region's industrial developments.

Sam is the younger brother of Bishop J. Dudley Love and a member of the local search-and-rescue team. He assists the heavily armed posse in tracking the environmental saboteurs through the harsh canyons, following his older brother's commands.

Susan is one of Seldom Seen Smith's three wives. She lives in Green River, Utah, maintaining a home for him to return to between his river-guiding expeditions and illicit sabotage runs.

Sheila is one of Seldom Seen Smith's three wives. She lives in a separate household from his other wives, representing the complex polygamist lifestyle he maintains across the region.

Hall is a police officer in Flagstaff, Arizona. He previously arrested Hayduke for public drunkenness, an incident Hayduke views as an unjust abuse of power and returns to avenge by stealing the officer's running patrol car.

Colonel Crumbo is a high-ranking officer in the Department of Public Safety. He is tasked with investigating the early destruction of the bridge over Glen Canyon and tracking the culprits, whom he accurately suspects will target the dam next.