Maryland area temporary storage facility along Rt 4 or I97

We will be camp hosting at Point Lookout, MD during the month of June and instead of heading home to Southwestern Virginia, we will meet up with a group from our church and travel to NJ on a mission trip. We will be travelling Rt 4/2 and then get on I-97

We are looking for a temporary storage facility from July 4 until July 13 for our 34' fifth wheel.

Any suggestions? I have called a few and no one has room from our RV.