National parks. Revising boundaries of Yellowstone, Grand Canyon, Mount Rainier, Rocky Mountain, and Sequoia national parks and establishment of Shenandoah, Great Smoky Mountain, and Mammoth Cave national parks, hearings, 69th Congress, 1st session, on S. 3176, S. 3427, S. 3428, S. 3433, S. 4073, S. 4209, S. 4258, and H. R. 9387, Apr. 27-June 2, 1926.