Tires: Off Road Tires, land surveying company, bias ply tires

Question
I have operated a land surveying company for the past 32 years in the southwest.  We have always operated 3/4 ton pickup trucks, sometimes in real off road (as in no road) situations.  In the early days we had 10 ply rated nylon tires.  They were "tough" and we had very little trouble with these off-road.  Now, our trucks come with 245/75R16 radials which are fine on road, but develop sidwall holes if they even come close to a piece of sagebrush or cactus, resulting in unrepairable tires, but costing even more in lost time productive time and frustration.  Are there some tires somewhere in that size that will withstand a little brush poking at the sidewalls.  Are there any bias ply tires anywhere anymore??  What is the solution??  

Answer
Roger,

You may have to do a little digging, and a little experimentation, but there are probably tires out there that will work.

BTW, No vehicle manufacturer is going to use these types of tires.  In fact, they assume - correctly for 99% of the population - that the 3/4 ton truck is going to stay on the pavement.  So the OE tires will not work.

What I would do is see about larger tires, and use lower inflation pressures.  This will probably require new rims.

And the place to go is a store that specializes in off roading.  They are familair with the problem and can probably offer the best advice.