On Sept. 30, 2026, the deadline for the U.S. Fish and Wildlife Service to decide whether to list the monarch butterfly as a threatened species was extended to June 6, 2030.
The binding date was set as part of a settlement in a lawsuit filed by the Center for Biological Diversity and Center for Food Safety against U.S. Fish and Wildlife Service, its director, Brian Nesvik, and Doug Burgum, secretary of the U.S. Department of the Interior.
In 2024 USFWS published its proposal to list the monarch as a threatened species under the Endangered Species Act. When it missed the December 12, 2025, deadline to issue a final ruling on this proposal, the plaintiffs sued “to compel the Service to publish a final listing determination … by a date certain,” according to the September 30 settlement agreement.
Before an animal species can receive federal protection under the Endangered Species Act, it must be added to the List of Endangered and Threatened Wildlife by the U.S. Fish and Wildlife Service, the premier conservation agency in the United States.
A threatened species is defined as “one that is likely to become endangered in the foreseeable future throughout all or a significant portion of its range,” according to an USFWS summary of the Endangered Species Act.
When it announced the 2024 proposal, USFWS encouraged the public to submit comments to be considered in the final decision. By March 2025 the agency had received more than 140,000 public comments, according to Birgit Rollins, staff attorney for the National Agricultural Law Center.
Referring to its most recent Species Status Assessment of the monarch, dated December 2024, USFWS states, “[B]y 2080 the probability of extinction for eastern monarchs ranges from 56 to 74% and the probability of extinction for western monarchs is greater than 95%.”
The population of eastern monarchs is measured by acres densely covered with monarchs in Mexico’s oyamel forests. Since annual monitoring began in 1993, the population has declined by an estimated 70%. This is attributed to agricultural use of neonic pesticides, destruction of milkweed, thinning of the oyamel forest by legal and illegal logging, extreme weather throughout the monarch’s range, climate change, storms, fire and drought.
In 1986 the Monarch Butterfly Biosphere Reserve was established by decree of President Miguel de la Madrid of Mexico. The reserve originally protected five overwintering sites within 39,680 acres. Today it encompasses 139,000 acres, spreading across the states of Michoacán and Mexico. Monarchs occupied only 4.42 acres in the Reserve in 2024-25 and 7.24 acres in 2025-26, according to World Wildlife Fund and Mexico’s National Commission on Natural Protected Areas, CONANP.
International governments are working with community partners to restore Mexico’s oyamel forests. Forests for Monarchs has planted 17 million trees. American Forests has funded the planting of more than one million trees since 2006. Forest geneticist Cuauhtémoc Sáenz-Romero has led massive replanting projects since 2015. From 2022 to 2024, World Wildlife Fund planted 160,000 saplings. In 2025, Colorado’s Butterfly Pavilion, in collaboration with the government of Mexico and community partners, planted 100,000 oyamel firs at higher elevations. Through a global program of Monarch Watch, individuals have created 58,776 certified waystations to sustain monarchs on their journey.
