I just attempted a run to the Cunningham Mtn. summit today and found the road blocked by a sign that read "CUNNINGHAM USERS GROUP - PRIVATE ROAD NO TRESPASSING" but it also had a phone # for info: 928-919-3927. If you want to request access though, I suggest you do so before going there -- you won't get any cell phone reception near there. :)
I was up Cunningham a few weeks ago and wanted to post a few updates:
There are no signs regarding Trespassing at the gate as of January 2016, and there's a fairly wide turnout for about 3 cars just before the gate.
Google maps found me alternate driving directions that are probably faster for those coming from the north. From Quartzite, head south on US-95 for about 6 miles and turn right onto the paved La Paz Valley Road. This is paved for about the first 1.5 miles, then becomes a decent single track dirt road. Follow this 4.5 miles to an obvious junction with Cholla Road and go left. This swings into the canyon and merges with the main road from above. Make note of this junction for the return if you want to leave via that route. There was only one spot going in and out of a wash that I thought would be tough for a low clearance vehicle.
In regards to the turnoff for the gate, it's actually at a 4 way junction with the main road continuing to the pass, and mining sites to the left and right. I missed this on the way in and had to backtrack.
A brief trip report: http://themtsarecalling.com/cunningham/