According to the Vaishnavas the Shaligram is the “dwelling place of Lord Vishnu” and any one who keeps it, must worship it daily. The Lord Krishna himself mentions the qualities of Shaligram to ‘Yudhishtir’ in the Mahabharta. All the Shaligrams are considered auspicious .
The legend, related at length tells us that Lord Vishnu for benefit of mankind in kaliyuga comes in earth in the form of Shaligram and in tulsi tree. Like the worship of Shiva in the form of a Linga, the worship of Vishnu in the shape of a Shaligram, is aniconic in character.
In the worship of Shaligrams, no initiation is required; there is no special rituals or specific procedure of worship, nor any need for a qualified priest . Worshipped by regular bathing saligram stones in curds, ghee, milk or water will give untold merit and will bestow all the benefits.
Saligram-stones are found only in the river Gandaki, which is a Himalayan stream, celebrated since history as Narayani, Saligrami and Hiranyavati. The scripture Mahabharata speaks of its sanctity (Bhishma-Parva). The Puranas also describe it as a sacred stream in which all the gods abide. By merely looking at it, one would eliminate all his mental stress, by touching it his bodily sins are burnt , and by drinking its water the verbal demerits are destroyed. One who comes into contact with this sacred water will be liberated from the cycle of birth and deaths, even if he/she be a sinner.