Instead of taking I-70, try I-64 east out of St. Louis to I-79, then I-68 to I-70, then either I-81 north to US 30, or continue to Baltimore and around I-695 to I-83.
I was thinking about suggesting I-64 as well. Though, one could also use I-70, I-270, I-70, I-70, I-670, I-71, I-76, I-80, I-99, PA 26, Harrison Road, PA 144, US 322, Front Street, I-83, US 30, Loucks Mill Road, and I-83 Business.
Taking Exit 35 on I-70 to MD 66 to MD 64 to MD 77 to US 15 to PA 234 to PA 462 to I-83 Business is another alternative.
My original suggestion was/would be I-70 to I-270 to I-70 to I-70 to I-470 to I-70 to I-79 to I-68 to I-70 to I-695 to I-83 to I-83 Business.