The crash, on Route 581 in Cumberland County, caused multiple injuries but none that were considered to be life-threatening, the Pennsylvania State Police said in a tweet.
The crash was reported shortly after 2 p.m. EST, according to the Patriot-News of Harrisburg, which cited a report from 511PA.
The pileup blocked all three lanes of the highway, WHTM-TV reported. Troopers are directing motorists to take alternate routes, according to the television station.
Traffic maps showed that drivers slowing to look at wrecks are delaying traffic, the Patriot-News reported.
It is not known when the highway will reopen, the state police said.
Photos: Late winter storm blasts South, Northeast A man walks through Lancaster City, Pa., with his shopping bag during a snowstorm Saturday, March 12, 2022. (AP Photo/Jim Gerberich)
Photos: Late winter storm blasts South, Northeast Willaim Dickerson, 4, runs across his front yard covered in snow in Tupelo, Miss., Saturday, March 12, 2022. (Thomas Wells/The Northeast Mississippi Daily Journal via AP)
Photos: Late winter storm blasts South, Northeast Ali Baker, 11, left, and her sister, Ava, 13, from Carrolton, Ga., start building a snowman at their relatives home, Saturday, March 12, 2022, in Tupelo, Miss., after an overnight snowfall left much of North Mississippi covered in snow. (Thomas Wells/The Northeast Mississippi Daily Journal via AP)
Photos: Late winter storm blasts South, Northeast A dog named Gilroy catches a frisbee thrown by his owner Jason Meyers of Burlington during a snowstorm, Saturday, March 12, 2022, in Burlington, Vt. (AP Photo/Jessica Hill)
Photos: Late winter storm blasts South, Northeast Ian Mattson, 9, throws a snowball at his sister Elise, 5, as they play in Renaissance Park on Saturday, March 12, 2022, in Chattanooga, Tenn. (Matt Hamilton /Chattanooga Times Free Press via AP)
Photos: Late winter storm blasts South, Northeast Ben Roth sleds down a hill along the banks of the Tennessee River with his son Avery, 4, on Saturday, March 12, 2022, in Chattanooga, Tenn. (Matt Hamilton /Chattanooga Times Free Press via AP)
Photos: Late winter storm blasts South, Northeast Snow accumulation is seen on a plant, Saturday, March 12, 2022, in Lutherville-Timonium, Md. (AP Photo/Julio Cortez)
Photos: Late winter storm blasts South, Northeast Ian Mattson, 9, throws a snowball at his sister Elise, 5, as they play in Renaissance Park on Saturday, March 12, 2022, in Chattanooga, Tenn. (Matt Hamilton /Chattanooga Times Free Press via AP)
Photos: Late winter storm blasts South, Northeast Jason Meyers of Burlington throws a frisbee for his dog Gilroy during a snowstorm, Saturday, March 12, 2022, in Burlington, Vt. (AP Photo/Jessica Hill)
Photos: Late winter storm blasts South, Northeast A city worker plows the sidewalk near Lancaster's Central Market on Saturday, March 12, 2022, in Lancaster, Pa. (AP Photo/Jim Gerberich)
Photos: Late winter storm blasts South, Northeast Marabella Martinez, 10, makes a snowman in Renaissance Park on Saturday, March 12, 2022, in Chattanooga, Tenn. (Matt Hamilton /Chattanooga Times Free Press via AP)
Photos: Late winter storm blasts South, Northeast A woman walks past a mural during a snowstorm, Saturday, March 12, 2022, in Burlington, Vt. (AP Photo/Jessica Hill)
Photos: Late winter storm blasts South, Northeast A man walks through Church Street Marketplace during a snowstorm, Saturday, March 12, 2022, in Burlington, Vt. (AP Photo/Jessica Hill)
Photos: Late winter storm blasts South, Northeast Snow and ice accumulate on a blooming cherry tree in Washington, Saturday, March 12, 2022, as temperatures dip into the into 20s. (AP Photo/Carolyn Kaster)
Photos: Late winter storm blasts South, Northeast Tristan McCroskey, left, and Randy Porter sprinkle salt on the icy sidewalk around the Tennessee Aquarium on Saturday, March 12, 2022, in Chattanooga, Tenn. (Matt Hamilton/Chattanooga Times Free Press via AP)
Photos: Late winter storm blasts South, Northeast Snow and ice accumulate on the buds of Yoshino cherry trees along the Tidal Basin in Washington, Saturday, March 12, 2022, as temperatures dip into the into 20s. (AP Photo/Carolyn Kaster)
Photos: Late winter storm blasts South, Northeast Deer walk across a snow-covered hill along Loch Raven Reservoir, Saturday, March 12, 2022, in Glen Arm, Md. (AP Photo/Julio Cortez)