I researched this question not only on the internet, but speaking to farmers in my area and they all agreed frost can occur until the last day in May. We are considered zone 5.
frost line in pa is 42 inches
its the last day of the month
in western pa the frost level is 3 ft. In New wilmington pa. just out side sharron
3 feet
September 24th.
It was 70 on November 22, 2010.
In western Pennsylvania the frost line falls at 36", when installing underground waterlines 42" is perfered.
42-44", but you can check with your local building inspector for a definitive answer.
According to something I read, the last GTR was in Colver Pa. The train was robbed of its cash payroll for the coal mines. The guard was killed and the robbers were later caught, convicted and executed.
Obama carried PA in 2008.
When was cabelas of hamburg pa open starting day
Star