Kurukshetra battle had ended and Yudhisthira had become the king of Hastinapur. But he had lost all the wealth in the battle. Sage Vyasa one day visited Yudhisthira and asked him to conduct the famous Ashwamedha yajna for the shanti of all those in the family who had died.
Yudhisthira, who was Dharmaraj, never lied and he told Sage Vyasa that he did not have the wealth even to give dakshina to visiting sages. It was impossible for him to even think about conducting Ashwamedha yajna which was a very costly sacrifice.
Then Veda Vyasa told Yudhisthira about king Maharishi Marut who once ruled the region. He had once conducted an Ashwamedha Yajna in the Himalayas. He gifted gold to all those people who participated in the yajna.
It was impossible to carry all the gold they received in dakshina. So people dropped all the gold they could not carry in a very large pit in the Himalayas.
Sage Vyasa then asked Yudhisthira to find the gold in the Himalayas and use it to conduct Ashwamedha Yajna.
It is believed that Dharmaraj Yudhisthira found the gold and took only that much which was required to conduct the yajna.
It is believed that the rest of the gold still remains hidden in the Himalayas.