Mosquito control in Garfield County

How to read mosquito trap data charts:
   • The species of mosquito that carries the West Nile virus is Culex tarsalis.

   • Culex mosquitoes are indicated in red in the pie charts.

   • The pie charts reflect the number of mosquitoes trapped in a single night in a specific location.

   • The charts breaks down the trap count by individual species.

   • Culex numbers that approach 50 or more in a trap in a single night, in a single location are a concern.

   • This number may lead to a limited, truck-mounted fogging of the affected area for adult mosquitoes.

   • When Culex counts approach 50, residents need to safeguard themselves to minimize their exposure to mosquitoes. See information below on prevention and insect repellents.

Mosquito control in Garfield County
Mosquito control operations in Garfield County

Air Show

Colorado Mosquito Control Operations Manager Steve Sheaffer searches for mosquito larvae and then treats for it in locations around Garfield County.
Mosquito control operations in Garfield County
Garfield County recognizes the risk of mosquito-borne disease associated with flood irrigation practices, urban development, and snowmelt runoff. The primary objective of the Garfield County Cooperative Mosquito Management Program is to suppress populations of larval mosquitoes in aquatic habitats. Adult mosquito trapping data is used to assess West Nile virus infection rates, as well as the need for adult mosquito control measures.

The Garfield County Cooperative Mosquito Control Program works countywide to provide cost-effective, integrated mosquito management operations. Along with Garfield County, all of the cities and towns in Garfield County participate in the program. Currently, Colorado Mosquito Control, Inc (CMC) acts as the contractor for the program using integrated mosquito management operations that utilize environmentally-sensitive controls and new technologies without negatively impacting the environment.

Periodically, adult mosquito populations become such that CMC must do an Ultra Low Volume (ULV) insecticide spray application in order to reduce adult mosquito populations to tolerable levels and to reduce human exposure to the West Nile virus. Anyone that would like to be notified when these mosquito spraying applications are to take place in their area or to ensure insecticides are not sprayed near their property should contact CMC Operations Manager Steve Sheaffer at (970) 644-1326.

The Garfield County Cooperative Mosquito Control Program also recognizes that many people are involved with organic farming and organic home gardening.  CMC has products that are certified for use on or near organic crops by the Organic Materials Review Institute (O.M.R.I.). Technicians are trained to apply these organic products to areas of larval mosquito production around organic operations.  For more information regarding O.M.R.I. certified products CMC has available, call (970) 644-1326 or e-mail to

Contacts and resources:
For further information, please contact:
Garfield County Mosquito Control Program, Garfield County Vegetation Management - (970) 945-1377 x 4305 

Garfield County West Nile virus prevention, Garfield County Environmental Health - (970) 625-5200 

Vector Disease Control International - (970) 644-1326

Public Health tips

mosquito West Nile virus prevention

Colorado Department of Public Health and Environment
The best defense against mosquitoes is to prevent their occurrence and keep from being bitten.

Protect yourself
Dusk and dawn: Avoid outdoor activities at dusk and dawn when mosquitoes are most active. 
Dress: If you are outside at dusk or dawn, cover up by wearing long-sleeved shirts, pants, shoes and socks.
Deet: Use mosquito repellents. Products with up to 30 percent DEET are recommended for adults and children over two months of age. 
Drain: Eliminate standing water in tires or other containers as these may serve as mosquito breeding sites.  Change the water in birdbaths and pet dishes frequently. If you have standing water around your home that you cannot drain consider using larvacide in the water.

Selecting an insect repellent
When it comes to discouraging mosquito bites, DEET is the gold standard by which all other repellants are judged. When compared to other active ingredients, DEET-based products provided the most complete protection for the longest amount of time. DEET is safe and effective when used according to label instructions. However, there are a variety of other options to choose from. For people looking for alternative active ingredients, including those derived from plants, there are resources available to help make the appropriate selection. The Environmental Protection Agency (EPA) website "Search for a Repellent that is Right for You" lists EPA registered repellents and the amount of time each is effective.

Shorter protection time does not mean the product is less effective. Key points to remember when selecting an insect repellent include:
  • Insects from which you want protection
  • Length of time you need protection
  • Active ingredient listed on the product label
  • Percentage active ingredient as listed on the product label

Be sure to use a product with a protection time that fits your activity. Keep in mind your results may vary depending on a number of factors:

  • Physical activity/perspiration
  • Water exposure
  • Air temperature
  • How attractive you are to mosquitoes and ticks; every person is different.

It is very important to re-apply repellent according to label instructions.

Fight the Bite Colorado Information about Fight the Bite Colorado, a West Nile virus prevention and education campaign

Mosquito control program annual reports

Mosquito trap data 2013-2018
Garfield County Cooperative Mosquito Control Program
annual reports

2018 Annual report
More reports
Vegetation Management
195 West 14th Street, Building D, Suite 310
Rifle, CO 81650
Email Vegetation Management

970-945-1377, ext 4305 | phone
970-625-5939 | fax
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