BOSTON — The Mashpee Wampanoag tribe said Tuesday that a recent legal opinion from the U.S. Interior Department could provide a major boost to its hopes of building a resort casino in Taunton.

Hilary Tompkins, the department’s solicitor, said in the memorandum dated March 12 that tribes did not have to be federally recognized before 1934 in order to be eligible to have land taken into trust by the Bureau of Indian Affairs.

The opinion sought to clarify the department’s interpretation of a 2009 U.S. Supreme Court ruling stating that the government was barred from taking land into trust for tribes that were not under federal jurisdiction in 1934, the year Congress passed a law specifying rights of self-government for tribes.