The main purpose of this legislation is to allow federally recognized Indian tribes to lease land held in trust for longer periods, specifically up to 99 years. This change aims to provide tribes with greater flexibility and security in managing their land, which can help them develop economic opportunities and improve their communities. The key provision of the legislation amends an existing law from 1955. It expands the authority for leasing land held in trust to include all federally recognized tribes, not just specific tribes mentioned in the original law.