Make sure you hit the ravines real good (I know you will). Many shells have been recovered in this area in ravines; back in the day when farmers plowed them up before becoming collectible they'd just chuck em in the closest ravine or low area so they wouldn't hit em again or get in the way. A couple of years ago they built a school adjacent to our sub-division, so everyone was hunting it pretty good as they cleared it before all the soil was removed and construction would start. After they cleared a particular low area/small ravine I hunted over many times but found nothing since the brush and trees were so thick before construction, this guy walks in on his first day ever of MDing went to this area we were working toward, and found 6 shells in about an hour all in about a 30' radius. All were different types and lol after he found his first one, a round shot, didn't know what it was - just held it up and asked, "What is it?" Well, we all just moseyed down there to check it out and tell him what it was. While we were passing it around admiring his good fortune he moved about 5' and dug a parrot shell and asked the same question since a different type. We again explained it was an arty shell and the type. He started catching on that big, fat iron objects were arty. All we could do was watch him dig the other 4 since we didn't want to be rude and hunt on top of his spot, and to be honest no one thought he'd pull 4 more out. Later told us it was his first day out ever and the machine he had was a Father's Day gift from the wife and kids. He seemed almost disappointed he didn't find any of the usual items you hear about, such as bullets and buttons, but we reassured him it was the day of a lifetime.
Best of luck man; hope you get a multi-shell day.