Sankshipt Itihas / Brief History
In Sadyug, when the Asuras were booned by Lord Shiva and they became very powerful and started terrorizing all living on the earth, the agonized Devtas there after went to Lord Brahma for a remedy. Lord Brahma sent them to Lord Vishnu. Lord Vishnu being helpless too, directed them to Lord Shiva for their protection. Listening to this Lord Shiva asked Mahamaya to take the roop of Mahakali and destroy the Asuras. Maa Kali took the roop and killed all the Asuras however could not cool down to normal after that and kept searching for more killings. Seeing this Lord Shiva took the roop of an Asura and fought himself with Maa. There happened a fierce battle for a very long time. The whole universe seeing this got terrorized.
Lord Shiva then thought of another alternative. He fell on the floor and when Maa Mahakali stepped on Him, she could see the clear roop of Lord Shiva, She immediately stepped back and cooled down realizing her mistake.
With this guilt and for the penance (prayshchit) of the same, Maa kept wandering and praying Lord Shiva in the Himalayas for thousands of years. And one day next to the Vyas river, at this place, Lord Shiva gave Her darshan and relieved Her of Her guilt. At that time a Shiva Lingam was established at this place and it became popular as Mahakali Kaleshwar Temple.
This place is also considered as the Maha Rudra Temple guarding the Maa Chhinnmastika Devi/ Chintpurni Devi in the eastern side.
According to a belief of the temple care takers and people around, every year at the times of monsoon, the flow of the Vyas River keeps increasing till the time it reaches itself to the Shiva Lingam. After the water reaches the Jalahri of the Shivling, it subsides.