For more detailed information, check out AA6XA's blog at https://longgreentunnel.blogspot.com/2019/10/w7ici-089-deadline-ridge.html.
Here are some confirmations/corrections: 1) You can indeed drive close to the summit and can access the actual summit with a high clearance 4x4, 2) The actual summit is not at the fence line but the SOTAMAPS location appears to be the accurate high point, and 3) The summit provides no place to attach an antenna mast and if using a mast guy lines are required.