To establish the Nantucket Sound Islands Trust, to preserve and conserve the said islands, and for other purpose.

Establishes the Nantucket Sound Islands Trust to provide for the preservation and conservation of the Nantucket Sound Islands. Creates the Nantucket Sound Islands Trust Commission to be composed of members, specified in this Act, appointed for a term of three years. Sets forth the boundaries of the Trust and provides for the classification of Trust islands.

Authorizes to be appropriated such sums as may be necessary to carry out the provisions of this Act, not to exceed, $20,000,000 for the acquisition of land and interests therein, and not to exceed $5,000,000 for development for fiscal years 1974, 1975, and 1976.