I like the trial tires on the front for the sand - MT43 for me.
I also like the Duro on the back for sand, but it is not DOT.
My sand riding has been on the Oregon dunes, Moab and around Quartzsite. Any ATV tire is going to give excellent sand traction.
Check out Freds new rear tire as he use to have the Duro or Kris's comments at the start of the tread I linked.