America's Natural Treasures of Immeasurable Quality Unite, Inspire, and Together Improve the Economies of States Act of 2018 or the ANTIQUITIES Act of 2018. This bill directs the National Park Service, Bureau of Land Management (BLM), U.S. Fish and Wildlife Service, Forest Service, and National Oceanic and Atmospheric Administration to administer each specified national monument under their joint or exclusive jurisdiction, including the Bears Ears, Grand Staircase-Escalante, Gold Butte, Cascade-Siskiyou National Monuments and the Rose Atoll and Pacific Remote Islands Marine National Monuments in accordance with: (1) the one or more presidential proclamations that apply to the applicable covered monument; (2) any Act of Congress enacted before December 4, 2017, that provides for an adjustment to the boundary or administration of such monument; and (3) this bill. The bill establishes the National Monument Enhancement Fund to furnish funding: (1) to such federal agencies to develop management plans for their national monuments that were designated under current federal law, (2) for federal acquisition and development of certain land and other areas, and (3) to develop and enhance recreational infrastructure on such designated lands. The bill designates: (1) specified BLM lands within the Organ Mountains-Desert Peaks and Rio Grande del Norte National Monuments in New Mexico and in the Gold Butte National Conservation Area in Nevada as wilderness and as components of the National Wilderness Preservation System; and (2) approximately 100 acres of BLM land in New Mexico as a potential wilderness area and, when specified conditions have been met, for incorporation into the Robledo Mountains Wilderness.