During Dwapara Yuga, Lord Krishna convinced the cowherd men to worship Govardhana, instead of doing a sacrifice to please lord Indra, the king of heaven, who is charge of the rain. Krishna told the cowherd men that Govardhana Hill was supplying so many necessities and should be worshiped instead.
“His reasons for discouraging the sacrifice performed to please Indra were twofold. First, as stated in the Bhagavad gita there is no need to worship the demigods for any material advancement; all results derived from worshiping the demigods are simply temporary, and only those who are less intelligent are interested with temporary results. Secondly, whatever temporary result one derives from worshiping the demigods is actually granted by the permission of the Supreme Personality of Godhead.
“Lord Caitanya has recommended that since Krishna is worshipable, so His land, Vrindavana and Govardhana Hill, are also worshipable. To confirm this statement, Lord Krishna said that Govardhana Puja is as good as worship of Him. From that day, Govardhana Puja has been going on, and is known as Annakuta. In all the temples of Vrindavan or outside of Vrindavana, huge quantities of food are prepared in this ceremony and are very sumptuously distributed to the general population. “The .cowherd men headed by Nanda Maharaja performed Govardhana worship and circumambulation of the hill. Nanda Maharaja and the cowherd men consulted learned brahmanas and began to worship Govardhana Hill by chanting Vedic hymns and offering prasadam. The inhabitants of Vrindavana assembled together, decorated their cows and gave them grass. Keeping the cows in front, they began to circumambulate Govardhana Hill. The gopis also dressed themselves very luxuriantly and sat in bull-driven carts.
Assembled there to act as priests for Govardhana Puja, the brahmanas offered their blessing to the cowherd men and their wives, the gopis. When everything was complete, Krishna assumed a great transcendental form and declared to the inhabitants of Vrindavana that He was Himself Govardhana Hill in order to convince the devotees that Govardhana Hill and Krishna Himself are identical. Then Krishna began to eat all the food offered there. The identity of Krishna and Govardhana Hill is still honored, and great devotees take rocks from Govardhana Hill and worship them exactly as they worship the Deity of Krishna in the temples. Devotees therefore collect small rocks or pebbles from Govardhana Hill and worship them at home, because this worship is as good as Deity worship. The form of Krishna who began to eat the offering was separately constituted, and Krishna Himself along, with other inhabitants of Vrindavana began to offer obeisances to the Deity as well as Govardhana Hill.”
After the cowherd men worshiped Govardhana Hill, Lord Indra became angry that he was not worshiped. He then sent torrents of rain upon Vrindavana. The residents of Vrindavana then approached Lord Krishna for help. Krishna then lifted Govardhana Hill and held it over the residents of Vrindavana like an umbrella. “The inhabitants of Vrindavana and their animals remained there for one week without being disturbed by hunger, thirst or any other discomforts. They were simply astonished to see how Krishna was holding up the mountain with the little finger of His left hand. Seeing the extraordinary mystic power of Krishna, Indra, the King of heaven, was thunderstruck and baffled in his determination. He immediately called for all the clouds and asked them to desist.”
After this, Indra came along with a Surabhi cow and offered prayers to Lord Krishna and then worshiped Him.