Originally Posted by Atlas
This is one of many, but there are also ideas of him being turned to stone by medusa's head. This is where the mount atlas thing comes into play...
It is interesting to note that another of the legendary myths in which Atlas played a part also involves the Hesperides. For it was one of the labors of Herakles to obtain the apples that were guarded by these nymphs who watched over the Golden Apple tree. In the legend, Atlas offered to assist Herakles in this task. The Titan then proposed a plan - he would retrieve the apples if Herakles would, in return, hold up the sky in his place. The hero Herakles agreed to this deal. However, Atlas had ulterior motives for helping. He would have left Herakles holding the heavens, but the hero either forced or tricked Atlas into taking back his burden. And so Atlas resumed his role as the tireless Titan who supported the sky on his shoulders.