American Indian tribes are looking to become the beneficiaries of the "green gold rush" as the legalisation of marijuana spreads from state to state.

With four states and Washington DC already allowing the recreational use of pot, and more expected to follow, cannabis cultivation is on the cusp of becoming very big business, especially with another 23 states already allowing pot to be used for medicinal purposes.

This is very good news for American Indians with as many as 200 tribes understood to be considering growing cannabis on their land.

They are able to do this because of tribal land's unique legal status, which has enabled them to cash in on the lucrative casino business for over two decades.

Now it is marijuana which is seen as a way of generating jobs on reservations and generating money for tribal administrations.