---
kind: "section"
citation: "16 U.S.C. § 228b"
title: "16"
title_heading: "Conservation"
number: "228b"
heading: "Composition of park"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/16/228b"
units:
  - "Chapter 1 — National Parks, Military Parks, Monuments, and Seashores"
  - "Subchapter XXIV — Grand Canyon National Park"
---

# §228b. Composition of park

- (a) **Additional lands, waters, and interests therein—** In order to add to the Grand Canyon National [Park](/usc/16/410r–5.md?p=c-3) certain prime portions of the canyon [area](/usc/16/539m–1.md?p=1-A) possessing unique natural, scientific, and scenic values, the Grand Canyon National [Park](/usc/16/410r–5.md?p=c-3) shall comprise, subject to any valid existing rights under the Navajo Boundary Act of 1934, all those lands, waters, and interests therein, constituting approximately one million two hundred thousand acres, located within the boundaries as depicted on the drawing entitled “Boundary [Map](/usc/16/430f–7.md?p=1), Grand Canyon National [Park](/usc/16/410r–5.md?p=c-3),” numbered 113–20, 021 B and dated December 1974, a copy of which shall be on file and available for public inspection in the offices of the National [Park](/usc/16/410r–5.md?p=c-3) Service, Department of the Interior.
- (b) **Abolition of Grand Canyon and Marble Canyon National Monuments—** For purposes of sections [228a](/usc/16/228a.md) to [228j](/usc/16/228j.md) of this title, the Grand Canyon National Monument and the Marble Canyon National Monument are abolished.
- (c) **Study and report to Congress of suitability of lands included within enlarged boundaries; submission date—** The [Secretary](/usc/16/410r–5.md?p=c-1) of the Interior shall study the lands within the former boundaries of the Grand Canyon National Monument commonly known as the Tuckup Point, Slide Mountain, and Jensen Tank [areas](/usc/16/539m–1.md?p=1-A) to determine whether any portion of these lands might be unsuitable for [park](/usc/16/410r–5.md?p=c-3) purposes and whether in his judgment the public interest might be better served if they were deleted from the Grand Canyon National [Park](/usc/16/410r–5.md?p=c-3). The [Secretary](/usc/16/410r–5.md?p=c-1) shall report his findings and recommendations to the Congress no later than one year from January 3, 1975.

## Source credit

(Pub. L. 93–620, § 3, Jan. 3, 1975, 88 Stat. 2090.)

## Notes

### Editorial Notes

### References in Text

The Navajo Boundary Act of 1934, referred to in subsec. (a), is act June 14, 1934, ch. 521, 48 Stat. 960, which was not classified to the Code.