In April 1984 members of 14 environmental groups in Palm Beach County came together to discuss a common concern – the preservation of a significant portion of the Yamato Scrub, which had been proposed for development. They concluded that the native ecosystems in the county were disappearing at an alarming rate and formed the Coalition for Wilderness Islands (CWI) to work on this issue. In May 1984 the Royal Palm Audubon Society, representing CWI, proposed a program to the Board of County Commissioners for the establishment of "wilderness islands" representing the variety of plant and animal communities native to the county. The Board supported this recommendation and contracted with Dr. Grace Iverson and Dr. Daniel Austin of the Department of Biology at Florida Atlantic University to conduct a biological survey to identify the remaining undeveloped lands in Palm Beach County that contained high-quality native ecosystems. This study, known as the "Inventory of Native Ecosystems in Palm Beach County," was conducted in 1987 and 1988.

During this two year-period, the Board approved the formation of ERM and set up a citizens' advisory group, the Environmentally Sensitive Lands Acquisition Advisory Committee (ESLAAC), to advise the Board on which lands to acquire. Based on the Iverson/Austin report, ESLAAC identified 38 sites as suitable for acquisition and recommended that 14 of these be given high priority for acquisition. In March 1991, after an effective citizen-supported educational campaign, the voters approved a $100 million bond referendum to buy these lands and others on the acquisition list.

Following passage of the referendum, the County took advantage of the State's recently-developed $3 billion Preservation 2000 Program and obtained state matching funds through the Conservation and Recreation Lands, Florida Communities Trust, and Save Our Rivers programs. Through the efforts of The Nature Conservancy, with some support from The Conservation Fund, the County's contractors for negotiations with landowners, the County saved millions more dollars by acquiring land at less than appraised value. The County's land acquisition program was so successful that voters approved another bond referendum in March 1999, this time for $150 million - $50 million for the acquisition of conservation lands, water resource lands, and lands for open space, and $100 million for acquisition of agricultural lands to preserve farming in the Agricultural Reserve.

Palm Beach County's land acquisition program set an example that was followed by other counties in Florida. In 1994 the National Center for Public Productivity at Rutgers University awarded Palm Beach County its Exemplary State and Local (EXSL) Award for having produced exceptional cost savings, measurable increases in quality and productivity, and improvements in the quality and effectiveness of government services. The County also received awards from the National Association of Counties and the Florida Association of Environmental Professionals for its land acquisition program.

By 2011 the County had acquired more than 31,000 acres of environmentally sensitive lands, ranging in size from 3 acres to over 12,000 acres, from the shores of the Atlantic Ocean to Lake Okeechobee and from the Martin County line south to Boca Raton. Public use facilities have been installed on many of these natural areas, the biological communities are being managed through prescribed burning and control of exotic species, school children are taking field trips to these sites, and the community is realizing the value of what has been preserved for future generations.