I agree that it depends on what the deer are used to. I have pretty regular ATV use on my property. However, we stop riding at the end of August unless we have to go for a particular reason. Most of the time, during the summer, the deer will watch us ride by, and then go about their business, unless we get too close. I hunt another area of about 800 acres, and we use a golf cart to get to the stands. Generally, who ever is in the farthest stand from the house drops off the person riding with them, and takes the golf cart to the stand. I parked the golf cart right out side of my stand (within 3ft) on a regular basis. The deer don't even pay it any attention. The will walk within 15 ft of the cart and just keep right on walking and never check up. I killed a 215# 9pt last year with the golf cart parked between me and the deer. He just ignored it.