The marriage of Shiva and Parvati is celebrated as Sitalsasthi for several years from now. No one is sure about the actual dates of its origin. However, from the records it is known that for the last 300 odd years it has been celebrated on the same day. This Hindu festival is in the form of a carnival. Where people and artists from different walks of life participate making it more beautiful and bringing out the true colour of life. Every year it is celebrated towards the end of the summer season (sixth day of the bright fortnight of the month of Jyestha), the aim being to call the rain Gods to give reprieve from the scorching heat of the Sun. During the carnival period Sambalpur attracts tourists from nearby states and abroad also.
Sitalsasthi is observed to celebrate the marriage of Gouri and Shankar - as depicted in the Shiva Purana. When Tarakasur was causing terror and devastation all over the world(Swarga, Martiya and Patala), all the Devata's approached Vishnu to find out a solution. Vishnu was undone; as Bramha had bestowed a boon that Tarakasura can only be killed by the son of Shiva. Tarakasura knew it well that after the death of his first wife, Sati (Dakshayani), Shiva was left bereft, withdrew from the world and roamed in the wilderness living a life of austerity and would never have a son; further Shiva was in deep meditation. Vishnu suggested all the Devatas to approach Shakti and request her to take birth as Parvati. On the request of all the Devatas Shakti reincarnate herself as Sati (Parvati) born as the daughter of Himalaya and grew into a supremely beautiful young woman. Narada told many stories of Shiva to Parvati and persuaded her to seek Shiva in marriage. Parvati set in meditation, but even after ages passed Shiva s meditation could not be broken. Again all the Devatas approached Vishnu to solve the problem. Suggested by Vishnu, Kamadeva took his bow and threw kamabana(Love Arrow) at Shiva. Shiva woke up and opened his third eye and burnt Kamadeva as a punishment; since then Kamadeva took the shape of Ananga. But as a result of this Parvati s meditation was fulfilled.
Before the marriage with Parvati, Shiva wanted to test her, to know how deeply she loves him. He incarnated himself as a batu brahmana(Short heighted Brahmin) and told Parvati that, Oh! Parvati, you are young and beautiful, why do you choose to marry an old fellow who lives in smasana (GraveYard), wears tree bark and snakes as ornaments. I know that Maheswara(Shiva) you want to marry, a half naked fellow, looks ugly, no one for sure knows his 'kula' and 'gotra', and how could you ever be happy with such a nomad. Listening to the suggestion of the batu brahman she got angry, and told Oh! Brahmana, ever after reading so much shastras you are still ignorant about Shiva, how foolish you are? I am not bothered whether he is old or young, ugly or handsome I am not marring him of his handsomeness, I am attracted towards him for his knowledge. I will not accept any one else other than him in marriage. Satisfied with all his test, Shiva appeared in his divine self. On the Jyeshta Shukla paksha Panchami they got married.
King Ajit Singh son of Chatra Sai of the Chowhan dynasty (1695 1766) ruled Sambalpur. As he was a Vaishnava in his belief & faith and used to spend a considerable amount time at Puri. He wished to establish Sambalpur as a religious place. In the ancient time Saiva upask (those who worship Lord Shiva) Brahmins were not present in Kosal. King Ajit Singh requested some Brahmin families from Puri to settle at Ajitpur Sasan (present day Sasan). This created displeasure amongst the tribal and other Brahmins and people of other castes residing in that area. To create harmony amongst the tribal and other castes he established several temples in the area. Ajit Singh understood that Sambalpur was famous as a Saktipitha in the ancient time, and the union of Shiva and Shakti were worshipped. Dewan Daxina Ray suggested the king to establish and contribute generously to the temples of the Astha Sambhu  in the area. The temple at Huma (The Leaning Temple of Huma) the abode of Lord Vimaleswar the chief amongst the deities of the 'Asta Sambhu was already built by King Baliar Singh; later Ajit Singh built seven other temples for the Sambhus. (Kedarnath of Ambabhona, Viswanatha of Deogaon, Balunkeshwar of Gaisama, Mandhata of Maneswar, Swapneshwar of Sorna, Bisweshwara of Soranda and Nilakantheswar of Nilji).
Keeping in view the famous Ratha Yatra of Puri, Ajit Singh started the Sitalsasthi Jatra/Yatra the marriage of Hara and Parvati at Sambalpur on the Jyestha Sukla pakshya Panchami. The God and Goddess are married like human beings. Thal Utha (Beginning), Patarpendi (Nirbandha), Guagunda (Invitation), Ganthla Khula are observed religiously. As during the Ratha Yatra, Jagannath is treated as a Ganadevata, likewise manner Shiva and Parvati are also treated as Ganadevata during this festival.
One nominated family acts as the father and mother of Parvati, and offers the hands of Parvati for marriage with Shiva. Since Shiva is Swayam Bhu no one acts as his father and mother.
Shiva starts his marriage procession along with other Gods and Goddesses from his temple. Hanuman and Nrusingha(Nrisimha) takes charge and leads the procession to the bride s residence. The family of the Goddesses welcome the barat procession (as we do in our marriages). The idols are kept in a beautifully decorated palanquin, the father and mother and other relatives of Parvati performs the 'Kanyadana' and the marriage is solemnised. The next day the procession returns to the temple (Mandir Pravesh ) with Parvati. Folk dance, folk music, different forms of other dances and music & different floats are the main attraction of this carnival.
Earlier only JhaduaPada and NandaPada were celebrating Sitalsasthi, since 1972 MudiPada has also joined the Carnival. A Joint Coordination Committee looks after the complete arrangement for the Carnival.