The road to Ironwood Forest National Monument from Interstate 10 at Red Rock exit winds first through a subdivision, then past a cattle feedlot and fallow cotton fields edged by rough-hewn wooden posts strung with barbed wire.
When the road switches to primitive dirt, the desert landscape reveals little beyond low-lying scrub bushes. The roadway appears freshly graded, but jumbled rocks at dry wash crossings mandate a high-clearance vehicle.
A small Bureau of Land Management sign about 25 miles northwest of Tucson marks the boundary of the national monument, and the start of lush foliage that includes towering saguaros and ancient ironwood trees.
President Bill Clinton designated the 129,000-acre monument in 2000 to protect elements ranging from endangered species to historical sites. A herd of desert bighorn sheep represents the only remaining native population in the Tucson basin.
Ironwood Forest is one of 21 western monuments currently under review, a move that intensified long-simmering battles over best uses for federal lands. Other Arizona sites include Sonoran Desert, Grand Canyon-Parashant and Vermilion Cliffs.
The appraisal began after President Donald Trump signed an executive order April 26 instructing Interior Secretary Ryan Zinke to review any national monument created since Jan. 1, 1996, that covers at least 100,000 acres.
The order requires Zinke to analyze whether previous presidents exceeded authority granted by the 1906 Antiquities Act, which empowers a president to protect cultural, historic or natural resources on federal land.
Presidents Clinton, George W. Bush and Barack Obama each used the Antiquities Act to create national monuments.
Trump said the act "does not give the federal government unlimited power to lock up millions of acres of land and water, and it's time that we ended this abusive practice."
Zinke said he would keep an open mind, but planned to examine whether any designations have led to "loss of jobs, reduced wages and reduced public access."
Opponents contend the designations interfere with traditional land uses such as ranching, farming, timber harvest, mining, oil and gas exploration, fishing and motorized recreation. Monuments located in Utah have generated the most anti-federalist sentiment.
Proponents claim overwhelming public support for protection of federal lands, pointing to a 2014 Hart Research poll that said more than 90 percent of Americans support presidential proposals to protect public lands and waters.
Figures released April 25 by the Outdoor Industry Association said outdoor recreation supports more than 7.6 million jobs and generates $887 billion in economic activity each year.
Locally, the Pima County Board of Supervisors approved a resolution 3-2 on May 16 to support the Ironwood Forest monument and to express concerns about the executive order.
Monument support groups including Friends of Ironwood Forest also oppose the executive order.
Friends president Tom Hannagan said rescinding site protection could lead to commercial development.
"This would amount to favoring a politically-connected few at the expense of the people," he said.
"No administration has ever tried to reduce or eliminate a monument named by a previous administration," Hannagan added. "Private parties have attempted this, but always lost in the courts."
Wilderness advocates including photographer Jack Dykinga also want protection to continue.
"We are dealing with a finite resource—the desert is really sensitive," he said.
Hannagan enjoys helping with half-day work hikes at the monument, toiling alongside fellow volunteers and BLM employees on projects that include trash pickup, plant restoration, geocoding and fence repair.
"It's work, but you're doing it with other like-minded people," he said.
The Friends host public "Meet the Monument" events in November and March that include nature walks and informational talks.
Volunteers work closely with BLM employees, Hannagan said. "We have a really nice relationship, and want to maintain that."