Just as Dross said, be very careful fishing the banks of a gravel pit, ive worked at all the open mining operations from cincy to cbus, almost all of them are undercut to allow them to get the extra material without having to pay to have the overburden taken off. If the gravel pit has any age to it, it is sure to hold monster fish. I agree with everyone else too, through live bait, cut bait out, try slip floats to control depth. The chance of there being any type of structure is slim to none unless it was put in. They will most likely hold to humps or ledges or along drop off along the bank. If it has hardly been fished no matter what you throw your going to catch something so you might be going for cats but get bass.