The goal of this project is to eradicate the american bullfrog from conboy lake national wildlife refuge or clnwr and a surrounding two mile buffer on private lands to eliminate american bullfrog…

The Department of the Interior Fish and Wildlife Service Region 9 Headquarters awarded MT. Adams Resource Stewards $1.261 million on November 1, 2025, under the Fish and Aquatic Conservation – Aquatic Invasive Species program (CFDA 15.608) to fund the final three years of American bullfrog eradication at Conboy Lake National Wildlife Refuge and a surrounding two-mile buffer on private lands in south-central Washington.

The project aims to eliminate bullfrogs from the refuge and adjacent private lands to protect the federally threatened Oregon spotted frog population. Bullfrogs, ranked among the world's top one hundred invasive species, prey directly on Oregon spotted frogs and displace them from habitat. Long-term diet studies at the refuge have documented bullfrogs consuming Oregon spotted frogs alongside numerous native species across four invertebrate classes and five native vertebrate classes. The bullfrog population at Conboy Lake is isolated with no natural reinvasion threat due to physical barriers to bullfrog movement. Four years of prior removal work beginning in 2020 have refined knowledge of bullfrog distribution and core breeding areas within the project area.

MARS, a local nonprofit administers the existing bullfrog control program through a cooperative agreement with the U.S. Fish and Wildlife Service. The organization employs six seasonal full-time technicians for the eradication program and has maintained high staff retention between field seasons. Work is performed in Glenwood, Washington, with a period of performance from November 1, 2025, through October 31, 2028. Conboy Lake National Wildlife Refuge historically harbored the largest Oregon spotted frog population throughout the species' range, making population recovery there a major milestone for overall species recovery.

The goal of this project is to eradicate the american bullfrog from conboy lake national wildlife refuge or clnwr and a surrounding two mile buffer on private lands to eliminate american bullfrog impacts on the federally threatened oregon spotted frog population. This proposal would fund the final three years of a bullfrog eradication effort that was initiated in 2020. The american bullfrog is considered one of the top hundred invasive species in the world due to its broad diet and high productive capacity and is not native to clnwr. The bullfrog is a direct threat to the oregon spotted frog through predation and habitat displacement. A long term bullfrog diet study at clnwr has documented that bullfrogs prey on oregon spotted frogs as well as numerous native species representing four classes of invertebrates and five classes of native vertebrates. Clnwr located in south central washington state has historically harbored the largest oregon spotted frog population throughout the species range. Recovery of the oregon spotted frog population at clwnr would be a major milestone for overall species recovery. The bullfrog population at clnwr is considered an isolated population. There is no threat of natural reinvasion from other watersheds because strong physical barriers to bullfrog movement exist. Four years of bullfrog removal work to date has provided a refined knowledge of the distribution and core breeding areas of the bullfrog population within the project area. The lead project partners are MT. Adams resource stewards or mars and US fish and wildlife service conboy lake national wildlife refuge. Mars a local nonprofit organization administers the existing bullfrog control program through a cooperative agreement with USFWS and is the proposed recipient of this funding request. Mars employs six seasonal full time technicians for the bullfrog eradication program. The existing bullfrog removal action team has maintained high staff retention between field seasons which has allowed the crew to develop a highly specialized skill set and greatly enhanced the efficiency of bullfrog removal efforts.project activities will be carried out according to the eradication plan. The conceptual framework for the project is to focus on the adult juvenile and metamorphic bullfrog life stages. Since 2024 project staff have implemented five main removal methods to remove more than 58000 bullfrogs from the project area. Methods are designed and employed specifically to protect native species during project implementation.recovery of the oregon spotted frog population at clnwr is the primary expected outcome as the oregon spotted frog population has already responded to bullfrog removal in an incredible way. Since 2021 the annual clnwr oregon spotted frog EGG mass count has increased by more than 900 percent from 147 EGG masses in 2021 to 1477 EGG masses in 2024. The 2024 count represents the highest count in the past 15 years and has resulted in the clnwr population once again establishing itself as the largest oregon spotted frog population throughout the species range. The ultimate goal is the threshold of 2900 oregon spotted frog EGG masses which is associated with the minimum viable population identified in the draft state of washington oregon spotted frog recovery plan. This is an important threshold because clnwr is the only oregon spotted frog population site in the east cascades recovery zone large enough to reach this minimum viable population. Clnwr supported more than 3000 oregon spotted frog EGG masses as recently as 2005 so a population increase to this level is feasible given the rapid increase in the past two years resulting from bullfrog control.