It happened October 15th in Winslow Hill, Elk County.
The Pennsylvania Game Commission says residents heard gunshots at about 3:00 a.m.
Later that morning, an injured 5- by 5-point bull elk was found hiding in a patch of goldenrod.
Authorities believe someone shot the elk in the front yard of a residence, and that the animal hobbled about 100 yards before collapsing.
The injuries left it unable to stand or walk. Game officials had to euthanize it.
Wildlife Conservation Officer Doty McDowell, who responded to the site where the elk was found, called the illegal shooting a senseless act.
"Whoever did this has no respect for elk, but also little regard for human life," McDowell said in a statement, pointing out the elk was shot near several homes. Individuals and groups in the area have pledged $3,800 in reward money for information leading to the arrest and conviction of the person responsible.
Elk were once endangered in Pennsylvania, but have rebounded thanks to conservation efforts.
Pennsylvania now sponsors a limited elk hunt each year, but illegally killing an elk out of season carries up to $15,000 in fines and up to 36 months in jail. Those convicted of illegally killing a trophy-class elk must also pay a mandatory $5,000 replacement cost.