A giant boulder in Arizona that went missing for weeks has mysteriously reappeared, only days after authorities announced it had vanished.

The 'Wizard Rock', a distinctive black boulder marked with striking lines of white quartz, is a well-known local landmark along State Route 89 in Prescott National Forest (PNF), near the centre of Arizona.

In addition to being an admired natural monument and stopping point for tourists, the Wizard Rock is also a hefty formation, estimated to weigh around 1 ton – so park officials were flummoxed to find it had gone missing.

"It's unfortunate when we lose a treasure such as the Wizard Rock," said district ranger Sarah Clawson for the Bradshaw Ranger District last week. Local residents had reported the absence in October.

"These boulders belong to the public, and should be enjoyed by locals and visitors for years to come."

(Prescott National Forest)

While the circumstances of the Wizard Rock's mysterious disappearance remain unexplained, they are not, in all likelihood, inexplicable.

In the last few months, at least one other known incident in the forest involved the unauthorised removal of a heavy boulder by individuals – but authorities point out you need some pretty serious equipment to move rocks this big.

"The easy way to do it would be a backhoe," PNF trails and wilderness manager Jason Williams told The Arizona Republic.

"But if you had a trailer positioned properly and didn't mind beating some things up, you might be able to do it with a Bobcat. But you surely aren't going to be able to do it any other way."

According to Williams, boulders of this size can be worth up to US$200 for the minerals they contain. Officials do point out that the removal of rocks and minerals (and other natural products) from national forests without a permit is illegal, with violations punishable by both steep fines and/or jail time.

Despite this, brazen boulder theft using huge tractors or front-end loaders is something that happens from time to time. As strange as it seems, these highly visible crimes can go entirely unnoticed.

"I think what happens is the general public, if they see somebody working with equipment in the forest, they see the equipment and assume it's an authorised thing," Williams said.

"It looks professional and they think they must be doing something the forest service has said 'go ahead' or even paid for."

That's a reasonable (if unfortunate) assumption, but in this case, if anybody did see the Wizard Rock being removed, nobody appears to have come forward.

Not that it seems to matter. Only days after Prescott officials announced the giant boulder's mysterious vanishing act, the Wizard Rock just as mysteriously turned up again, with a PNF employee on patrol of the Prescott Basin discovering the rock's return on Friday morning.

Forest officials have indicated they won't be investigating further, and are just happy their famous boulder has 'magically' reappeared.

"We are thrilled the Wizard Rock was returned, and are grateful that whoever took it was conscientious enough to give it back to the public," Clawson says.

"National Forests provide so many benefits to the American people, and when something like this happens, it highlights the intrinsic value of natural beauty in all its forms."

While we can't be sure why or how the Wizard Rock came to be returned, the forest authorities had hoped that by going public, they might be able to appeal to whomever was behind the boulder's disappearance.

A decade ago, a similar thing happened in the region, when a distinctive heart-shaped rock disappeared from the top of Granite Mountain.

After media coverage of the incident, the heart rock was returned anonymously, with the individual responsible explaining they didn't know the rock meant so much to so many people.

Of course, local happenings like this – much like the Wizard Rock itself – are curiosities mostly of interest only to people in the area, even if they occasionally blow up to capture national and even international attention, just as the Wizard Rock's saga has.

When it comes to forests, though, that broader attention is never misplaced. Across the US, Europe, and the planet as a whole, forests and the trees within them are under threat, as are the countless other living species struggling to safely inhabit these vital natural spaces.

The Wizard Rock might be just a single boulder, but its strange comings and goings also serve as a valuable reminder about respecting the sanctity of these environments, and the things that have a home within them - for the benefit of us all.