Last time I turned around and aborted the trip was in Wyoming's Wind River Range. The cause was medical issues with my late dog Hysson, who got into spells of vomiting. It turned out to be just his sensitive Lab stomach, but of course vomiting in dogs can turn out to be a symptom of something serious requiring immediate surgery. The second morning this happened, I decided no way was I going to continue. We wandered back to a few miles from the Green River Lakes trailhead; I set up camp and we rested for a day while I fed Hysson very small amounts of food every couple of hours. It worked; the next day as we were ready to leave, Hysson felt good enough to run around the meadow several times at top speed! I kept doing the frequent small meals for a couple more days, as we made our way (by car) back to Oregon.