This location along Highway 313 (Dead Horse Point Road) marks the location of where 15 year-old Dennise Sullivan was abducted in 1961 outside Moab, Utah.  Over 63 years have elapsed without a trace of her.  More info below:

Dennise resided with her mother, Jeannette D. Sullivan, and her four-year-old sister in Rockville, Connecticut in 1961. Jeannette was divorced and worked as a seamstress.  An acquaintance, Charles E. Boothroyd, asked them to go on vacation with them to Utah that summer. Jeannette and Dennise agreed to join him, leaving the younger child at home with Jeannette's parents. The travelers were driving Boothroyd's olive-green 1960 Volkswagen. Photos of Boothroyd and Jeannette are posted with this case summary.

On July 4, 1961, the trio met a man near Dead Horse Point, seventeen miles outside of Moab, Utah. He was heavyset, with black hair and a dark complexion. He spent two hours with them, telling them the history of the area while they took pictures. He drove away in a tan sedan without telling anyone his name.  Boothroyd and the Sullivans planned to spend the night in Moab and it was getting dark, so they too left at this point.

Just a short distance down the road (at the time is was gravel), around the bend, they saw the man they had spent time with earlier. He was pulled off to the side of the road, lying underneath his car.  They stopped to ask if needed help and the man said he was having engine trouble and asked for a flashlight. After Boothroyd gave him the flashlight, the man threatened all three of them with a .22 caliber rifle and demanded money.

Boothroyd laid his wallet on the road and Jeannette removed $250 from her purse, threw it on the ground and started to walk away, but the man shot her in the back of the head and shot Boothroyd twice in the face. Boothroyd survived his injuries, but Jeannette was killed almost instantly.  The shooter rolled her body into a nearby ravine and left Boothroyd lying on the ground. Dennise attempted to drive Boothroyd's car away, but the man chased her in his own vehicle, ran her off the road after half a mile at this location, then dragged her into his own car and drove away.

An oil worker at a rig two miles away heard the gunshots and the sound of the cars driving off and went to see what was wrong. He passed the abduction car speeding down the road and then the wrecked Volkswagen, then drove on and found Boothroyd still conscious by the roadside. Boothroyd told him what he'd seen, and the oil worker called for assistance on his radio.  Two hours passed before an ambulance arrived to take the wounded man to the hospital, and the law enforcement came shortly after that. They launched an extensive search of the area for any sign of Dennise or the kidnapper.

The prime suspect in the kidnap/homicide is Abel Benny Aragon, an unemployed coal miner who lived in Price, Utah. A photo of Aragon is posted below this case summary. His vehicle matched the description of the abduction car. When the FBI stopped him for questioning on July 6 at Crescent Junction, Utah, Aragon shot himself in the head with a .22 caliber pistol. He was rushed to the hospital, but died two hours later without regaining consciousness. It was the day after his 35th birthday.

Aragon was a Marine veteran who was awarded the Navy Cross for heroism during World War II, and he had no criminal record. Witnesses reported seeing him alone at 2:00 a.m. on July 5, about four and a half hours after the shooting at Dead Horse Point.  He stopped a truck driver, gave him an envelope and asked him to mail it. The envelope contained money and a note addressed to Aragon's wife, telling her he loved her and their five children. It didn't mention any crimes.

Five hours after the shooting, Aragon arrived at a mining camp at Polar Mesa, where he had stayed several times before. When authorities searched the area on July 10, they found some of his clothing. Nearby, under a rock, they found the .22 rifle that had been used in the shooting, and hidden in the brush was a shovel identified as Aragon's.  Authorities determined from the paint scratches and other damage to his car that it was the same vehicle that rammed into Boothroyd's car and forced it off the road. They also found a set of Aragon's tracks, and a smaller set parallel to them, believed to be Dennise's. They never found any trace of Dennise herself, however.

Foul play is strongly suspected in Dennise's case due to the circumstances involved. An exhaustive search turned up no sign of her. Her body may be somewhere in the Polar Mesa area or in the Colorado River.

From: https://charleyproject.org/case/dennise-jeannette-sullivan