midnight
They milled a long while before they bedded , and more of them than usual stood up to watch . Not a rider had been seen all day . Through the baking glare there had moved a cloud of suffocating dust , and under it the thirsting , snorting , blethering sheep , with the dogs on the edges and the men farther out at regular intervals along the line . After supper some of the men slept , for it was not planned to start the sheep until midnight , as they needed the rest , being footsore with long traveling . It was calculated also that they would reach the ford at the Big Horn by shortly before dawn . But the sheep would have none of it , and moved and milled uneasily until , in order to save the lambs that were being crushed in the narrowing circle , Sims gave the order to resume the march . The night `` walk '' of sheep is a strange thing .