Hi Gerard ,
Yes they will get very close . My wife's hobby is to see how close she can get and take there picture . I think she has gotten within 20 feet by using the trees as cover . I have driven by them in the truck and they were within 50 feet and never stopped eating grass . The mama's were here all summer with their calf's and it was very entertaining .
I practice "cow calling" to them sometimes in the evening . It can get real exciting when one of the bull's comes sneaking in to see who the new girl is !
We also have a pair of perfect 6x6 Whitetail bucks that like to hang out with this herd .They also have a pair of brothers that are perfect 5x5's . Here is a picture of one of their little brothers . He is a 4x4 . No kidding , the same doe is the mother of these three sets of twins .
They just melt away during hunting season and then show up again after season closes .