I would take a purifier for sure. Most antelope country that I know of is also cattle and sheep country. The water is not safe to drink, gerardia comes to mind first. Katydyn is the brand I have been using. but I haven't really used it on more stagnant water like stock ponds. I would stick to the creeks where at least the water is moving, but still purify it. The creeks can be pretty seasonal, too, so that is something to look at, too. I haven't tried the iodine tablets or anything like that, if nothing else boil your drinking water and cooking water. Even in a desperate situation, skin some cactus before you drink the water.