Wayne --
I had looked at the Cooper Discoverer ST Maxx as my summer tire for my dually, because they had a much harder, cut resistant tread. Very appealing for driving on shale, cinder or basalt based forest service roads and hopefully the >400 miles of gravel road to Inuvik, NW Territories, Canada.
At a slightly greater cost per tire, you might also consider
Toyo M55 tires. Very cut resistant tread. Available in LT235/80 R17 120\117Q E. I ended up with the Toyo M55 LT265/70 R17 121/118S E for my dually. They have held up really well for the past four years.