A 37-year-old man is facing charges after authorities say he threw boulders at passing vehicles along a stretch of U.S. Route 6 in Utah County, damaging cars and windshields before police used drones to track him down and took him into custody at gunpoint. The incident happened Saturday around 7:38 p.m. between mile markers 208 and 209 on Route 6 heading toward Price.
According to FOX 13 Salt Lake City, dispatch received reports from callers describing a male throwing rocks at vehicles, with at least four people calling 911 to report a man jumping in front of cars and hurling rocks. One caller reported that a male dressed in dark clothing threw a boulder at their vehicle up the canyon toward Price. Callers told police the man damaged multiple vehicles, including windshields.
Drones Help Officers Close In
Police deployed drones to help locate the suspect along the highway corridor, per the station's report. Officers eventually noticed a person walking on the highway shoulder who matched the description given by callers. As officers approached, the man reportedly shouted something about someone being after him, according to the police report cited by the outlet.
Officers ordered the man to surrender at gunpoint before taking him into custody. Police identified him as Nicholas Sean-Leo Proulx, a 37-year-old Salt Lake City man, who was arrested for allegedly throwing boulders at passing cars along Route 6 in Utah County.
A Dangerous Stretch of Highway
The corridor where the incident occurred has a grim history. More than 20 people have died in traffic crashes along a 42-mile stretch of U.S. Route 6 starting at the mouth of Spanish Fork Canyon since 2020, according to Utah Highway Patrol data reported by KSL.com. The canyon's narrow lanes and high speeds have made it one of Utah's deadliest highways, prompting the state to pour resources into fixing it.
A Utah Department of Transportation concrete median barrier project between Diamond Fork Road and the U.S. 89 junction is intended to prevent crossover crashes and was expected to last until the end of the year.
How Utah Law Treats Rock-Throwing as a Weapon
Throwing heavy objects such as boulders at occupied vehicles can pose serious risks. Under Utah Code Section 76-5-103, aggravated assault can carry potential prison sentences of one to 15 years when serious bodily injury occurs or strangulation causes loss of consciousness, according to Overson & Shewmaker Law.
The danger of throwing rocks at highway speeds has produced fatal outcomes elsewhere. In April 2025, a Colorado jury convicted a 20-year-old man of first-degree murder after a 9-pound rock thrown from a vehicle through a windshield fatally struck a 20-year-old driver on a highway in April 2023, as reported by AP News.
Utah has also seen a recent pattern of similar arrests. In September 2024, a 40-year-old man was arrested in Sandy after throwing a softball-sized rock through the window of an occupied Utah Transit Authority police patrol car, according to a separate report.
A Broader Pattern on American Highways
Hoodline has tracked repeat overpass arrests in other states, including a St. Louis man charged with three felony counts each of assault, property damage, and armed criminal action after throwing large rocks from an Interstate 64 overpass into moving traffic. Open questions in the Utah County case remain, including the final formal charges to be filed by the Utah County Attorney's Office, the full extent of damage and any injuries reported by the four callers, and whether Proulx's reported statements to officers will prompt a mental health or competency review.
