About Us

Grant County Mosquito Control District's origin began in the mid to late 1950's when Columbia River irrigation water was introduced in the Columbia Basin.  The local population in and around the city of Moses Lake and Larson Air Force Base suffered from devastating mosquito infestations. Mosquito infestations resulted in encephalitis cases causing death or permanent mental and physical disabilities. 


According to Grant County Health Department historical documents, citizens rallied around the mosquito abatement cause taking action through public hearings and meetings, legislative measures, and donation drives.  From a historical prospective to highlight the gravity of the problem, in 1958, local groups generated $10,685 in 3 days (equals $86,172 in 2013) from canvas donations! The 3-day drive provided the entire funding for the entire year.













                           1958 Dipping Cup Showing Mosquito Larvae                                2014 Dipping Cup



Under the direction of the Moses Lake City Public Works, the Moses Lake Mosquito Control Authority was formed, and mosquito control boundaries were established.  Materials, equipment, and personnel were purchased and hired.  The 1958 mosquito control framework, procedures, and methods still exist today and are standard throughout the United States. 


























1958 Mosquito Control Zones matched School District Boundaries



However, the District was deactivated in 1959 due to lack of consistent funding.  In 1964, the District was reactivated with limited resources and funding due to actual need and threat of disease.  Grant County citizens continued to promote a special tax assessment for mosquito control and on 15 September 1964, a special election was held, and the special tax assessment for mosquito control passed with 70% of the vote.  As a result of the election, the name was changed to Grant County Mosquito Control District #1 (GCMCD) to more accurately reflect the special tax assessment area of nearly 600 square miles of Grant County. 

































Current GCMCD Boundaries, approximately 600 Square Miles


GCMCD has matched the City of Moses Lake and Grant County as its population, agriculture, aviation, recreation, and businesses have thrived and grown through improvements in technology and efficiencies. 


In the mid-1980s, the District drastically improved efficacy through the purchase of a fixed wing aerial application aircraft which allowed mosquito-specific products and techniques to be delivered on a massive scale.  Since that time, an aerial application has become a staple in sound mosquito management plans throughout the United States. 






















GCMCD’s Larvicide Aircraft, 2016 Thrush 550 P


Today, GCMCD’s Integrated Mosquito Management Plan is two-pronged.   The District's primary control mechanism is to target the estimated 15,000 acres of wetland mosquito habitat with specially formulated products to kill the mosquito larvae during their approximate 7-day water life cycle before emerging as adults.  Over the past 50 years, GCMCD has refined its techniques and procedures to improve control.  One of the most significant changes occurred in 2010 when the District shifted to a granular larvicide program which is a better product delivery method and dramatically improved efficacy.


However, due to the sheer number of mosquito larvae and associated habitat, it is impossible to eradicate mosquitoes and a percentage escape and hatch into adults.  At a point when the adult population becomes a significant source of disease and/or nuisance, GCMCD then utilizes the second approach of adulticiding.  Mosquito adulticide is applied via ground-based fogging applicators utilizing vehicles such as pickups or all-terrain vehicles, but, this method is only successful at treating a very limited geographical area.  To combat this limitation, GCMCD utilizes an aerial application for large areas covering up to 10,000 acres in one flight.
























GCMCD’s Adulticide Aircraft, 1969 Cessna Skymaster 337


District Boundary Map Better.jpeg