ga.ngA dharar : Lord wearing ga.ngA (river to head).
bhagIratha was the renowned king forefather of rAma of raghu vamsa. His forefathers known as sagaras were burnt down due to a curse. For the upliftment of those ancestors from the cursed state to get to the heavens, he wanted to bring the river ga.ngA to earth. The idea is that when ganga waters touch the ash of sagaras, they would be uplifted from their sin. He did very severe austerities and to get the permission from indra. He gave permission to bring the ganaga flowing in the heaven to the earth, however he told, coming down to earth would be the decision of ganga. So bagIrata again started his penance and prayed the goddess ga.ngA. She agreed to come down, but warned him that he should find a person who could withstand the force with which she will descend to earth! He agreed and found out that the refuge would be at Lord shiva. He did the austerities pleasing Lord Shiva. Appreciating his devotion and efforts, Lord agreed to hold the ga.ngA when she descends to earth. ga.ngA out of her pride and ignorance thought that the Lord won't be able to withstand the force! She came down with an intention to gush down the Lord with heavy force. Can the Lord, Who holds the entire world He created, be pushed down by a river ? The Lord, who is the creator of the entire universe and who has taken the forms just out of the grace on creatures, arrested her flow in His matted hair! She tried her best to rush out of His matted hair, but in vain. Not a drop of water could escape! bhagIratha, worried by this (as he would not get ganga to earth otherwise), prayed to the Lord to show mercy on her. The Gracious Lord allowed the ga.ngAthrough a strand of His matted hair. ga.ngA then flowed humbly, gracefully and giving prosperity on her way to pAtALa. Thus the ancestors of bhagIratha were resurrected by the holy water of ga.ngA.
The Lord in the posture holding the ganga in the matted hair is called gangAdhara mUrthi.