The watermelon happens to be for Bigfoot, another one of the inhabitants of the bucolic town on the outskirts of the Navajo reservation.
"My grandma left it for him," says Felicia Frank, who lives nearby. "I said, "Grandma, you're feeding Bigfoot?'"
Down the road, Frank points out where several people have sighted the legendary, hairy being, along with other odd species.
"Things like this happen all the time on the rez," she says, noting that it is not just in Upper Fruitland that these extraordinary sightings occur.
It's just a matter of getting people to talk about it.
Talk about taboo
By driving though the Navajo reservation, no one would know that the vast tribal land is thought by cryptozoologists to be home to so many outlandish species.
"Navajo stories go way back, for years," said Leonard Dan, a self-proclaimed cryptozoologist, someone who studies animals thought to be extinct.
"There have been sightings of Pegasus, and of Griffins," Dan said, referring to two creatures thought by most to come from Greek mythology.
Lately, an unusual number of people on the reservation also have spotted Centaurs, another animal of Greek mythology that is human on top and equine on the bottom.
"I had more reports of Centaurs than Bigfoot this
Many people, however, fear talking about what they see because of the traditional taboos that surround many creatures.
Just as many common animals have meaning in Navajo spirituality, so too do some of the atypical ones, Johnson said.
Some believe that if a person sees Bigfoot, they will die a year later. If a person sees a miniature tyrannosaurus rex, also believed by some to be alive on the reservation, they might turn to stone.
Even those who don't believe in such superstitions struggle to bring up the topic.
Brenda Harris, also of Upper Fruitland, said it took her a while to talk about her sightings of a pterodactyl, a winged Jurassic dinosaur, in the late 1990s because she was wary of the humiliation.
After talking about it, though, she found many of her neighbors had similar experiences.
Getting to know the unknown
"A lot of people are opening up," she said.
So many people, in fact, have opened up that nationwide media have zeroed in on many of the strange events that have occurred on the reservation.
National Geographic's show "Navajo Cops" featured an episode in which the police tried tracking the Newcomb "Howler," thought perhaps to be a lonely Bigfoot or a skinwalker, an evil Navajo witch that changes form.
Still, not all law enforcement are very responsive when reports involve sightings of weird creatures, according to the people that have called on the police to investigate sightings.
"Different folks, different strokes," said one Navajo police criminal investigator from Shiprock. He did not want to be named.
"As far as looking for the Lochness monster in the San Juan River, we're not going to do that," he said, adding that he respected people's beliefs but did not often have time to entertain them.
While some residents have grown used to the idea of the bizarre assortment of species on the reservation, others truly fear certain types.
Just recently, one Upper Fruitland family spotted a red-eyed, three-clawed, winged creature comparable to the demonic being in the 2001 American horror film "Jeepers Creepers." The family named it the "Night Stalker."
It has left claw marks on their home, on their car, and even has managed to scratch their daughter during her sleep.
Johnson has made it his mission to document these cases, especially when law enforcement fails to.
Johnson has independently researched all kinds of cases, from behemoth snakes to werewolves to upright hooded lizards that will shoot poison into a person's legs and then eat them. Not to mention skin walkers, the evil Navajo spirits that are known to take the shape of a wolf, among other animals.
"The locals out there all know about it," says Johnson.
While he works independently for the most part, he sometimes calls the Navajo criminal investigators in to give his research an added credibility that is, if they will come.
Oftentimes, the Navajo police do not want to respond because of their own superstitions, or simply because they do not find the matters important.
On a reservation that is steeped and crime and short on resources, only a few officers find the time to make it out to cases that sound a little bit "out of this world."
And, if they do find valuable evidence, they confiscate it immediately.
"They just show up in a black van," said Harris, who has heard of several instances when the police have told people to repeat nothing of what they saw and forget the sighting ever happened.
Real life monsters
As Johnson and Dan walk near the river with a few of the Upper Fruitland residents that have seen some of the odd species that the two local cryptozoologists are so interested in, Johnson picks up the watermelon on the ground.
Johnson looks at it, places his hand around it as he imagines Bigfoot might have and inspects some of the markings, which look like they are from some kind of animal.
"This might have been Squatchie," says Johnson, who also affectionately refers to Bigfoot as a "furry bastard."
Still, he says, it may not have been. No track marks. No broken branches.
"I'm not trying to convince anyone of anything," Johnson says, noting that it is important not to have an agenda when pursuing evidence of the unknown.
"It's just the truth," says Harris.