Answer:
Native American reservations are assisted by the Department of Interiors (DOI).
Step-by-step explanation:
The department of Interiors (DOI), formed on March 3, 1849, is a federal executive department of United States’ government which is responsible for managing and guarding most of the federal area/land and natural resources.
Due to the broad range of responsibilities, this department of Interior (DOI) is also called (humorously) as “Department of Everything" because as the other nation’s interior ministries which are only addressing police matters and internal security, its role is beyond it.