What is "sarnaism"

Sarnaism or Sarna (local languages: Sarna Dhorom, meaning "Religion of the Holy Woods") defines the indigenous religions of the Adivasi populations of the states of Central- East India, such as the Munda, the Ho, the Santal, the Khuruk, and others. During the colonial occupation of India, the British neglected recognizing Sarnaism as a distinct religion belonging to the larger family of Indian religions; because of this negligence, Sarnaism was "subsumed" as a folk form of Hinduism. In recent decades, adherents and followers of Sarnaism have developed an identity, and more recently even an organisation, distinct from Hinduism, similar to other tribal religious movements such as Donyi-Polo or Sanamahism.