I had heard from another highpointer on Harney Peak, SD that she charged $20/car to access White Butte, so I purposely took all but $5 out of my wallet before I got there. Then, when she brought up the $20 fee, I reached for my wallet and said "Oh, I don't think I have $20. All I have is $5." She was nice enough to accept the $5 as full payment. She said since I was alone she'd make the exception. Thus, I scored a deep discount there, thinking it outrageous to spend $20 to climb that high point. However, she was a very nice lady that I found very easy to chatter with. I don't feel at all bad about my subreption.
The owners have a mail box placed at the last intersection before the old homestead (or about 1/8 of a mile before the abandoned homestead) for depostion of the required fees.
I did this yesterday and wanted to put the current details. From Main St. in Amidon go ~ 2 miles north and then turn right onto an unmarked gravel road. From there drive ~ 4.8 miles and turn right onto a gravel/dirt drive. From there it's ~ .9 miles to a donation mailbox (see images). According to HighPointers.org the expected donation is $10. Turn left at this point, don't continue to the farmhouse. The road at this point is passable in a sedan if the weather has been nice. I was lucky that it was dry as I'm sure in worse conditions it would be difficult. Consider parking at the mailbox if you're unsure about the road as it's only a mile to the trailhead. However, from the mailbox you can go .7 miles to a wider spot where hikers are encouraged to park. You may also go another .2 miles on slightly rougher road at which point the road ends and there's a gate to the trail. Obviously the gate is there for a reason so please close it completely. The trail is clear enough and moderate difficulty. WATCH FOR SNAKES. We came within inches of stepping on a rattlesnake and one other snake of undetermined species. Views are great, you may see some other wildlife, it's a nice high point to complete.