There is water available only at Pine Springs (campground and visitor's center) and McKittrick Canyon visitor's center. On the trail, I saw none at all (except for the rain!). Even if you find water, they ask that you leave it for the wildlife. I think the water situation is the only thing keeping this park from being a short-trip backpacking Mecca. We "cameled up" and carried 3+ liters each. The weather wasn't too hot, or I might have wanted more. This was for a single night out and then back to Pine Springs for a refill before a second night out (which didn't end up happening, but that's another story).