Rinse and dry the venison. Salt and pepper liberally. Mix the oregano and the cumin with olive oil and rub all over meat. Place the venison in a slow cooker and top with the onion, garlic, and jalapeno. Squeeze over the juice of the orange and add the two halves. Cover and cook on low for 5 to 8 hours. Reserve liquid.
Once the meat is tender, cook to about 200 °F, remove from slow cooker and let cool slightly before pulling apart with 2 forks. Remove to a large bowl.
When meat is ready pull, temperature should be 195-210°F.Store leftovers in the refrigerator for 3-4 days.For longer storage, freeze in packages large enough to accommodate one meal for your family. Stores for 6 months, if well packed.