Down hill from the truck a calf will do nice Seriously, usually the slick perty looking cows are young and lack in poundage and are good breeding stock, I look for the cow that looks rougher, head looks big and rough, body usually seems boxier than the younger cows and I try to watch long enough to pick out a dry cow. These are the older cows and you can at close to 50lbs more meat over a young cow and they are soooooo good eating but drag like a battle ship anchor!!
My favorite part about cow hunts is that you don't have to hold out for a bigger rack you can just shoot the first one you want to I usually try and find them a little closer to the road then the bulls so I don't have to haul them out quite as far. A calf or a dry cow (depending on how much meat you want or where you find the elk) will be your best bet. Good Luck!
For many years I would always try to shoot the lead cow because she was most times the biggest. One year I shot a smaller cow. I can still smell the elk stew and corn bread!!!