In the United States, use of wind farms to generate electricity has recently grown dramatically. When wind farms are within the line-of-sight of weather radars, they can affect data quality and the performance of radar algorithms. Because of possible impacts to the NEXRAD Radar Program, the Radar Operations Center and the University of Oklahoma are studying wind farm radar returns to document current impacts and work on mitigation steps. This paper focuses on analysis of data from two WSR-88Ds: Dodge City, KS (KDDC), and Great Falls, MT (KTFX). KDDC has two wind farms within line-of-sight: Northeast Wind Farm at 20-24 km range and Southwest Wind Farm at 36-40 km range. KTFX has only one wind farm, but it is at very close range (~6 km) and produces inter-turbine scatter and multi-trip echoes that can expand wind-farm-related-return to extended ranges. This paper documents if and how often wind farm returns are seen by the radars and the resulting impacts. Continuous climatologies have been collected in winter and spring months. Factors influencing how often the wind farms are “seen” by the radars are clutter filter type, wind speeds (better suppression for light winds), and vertical temperature stratification/beam propagation conditions (inversion/ducting is worst case). Some of the radar return is from the turbine towers (0 velocity) and some of the return is from the spinning turbine blades (at up to high wind speeds), creating disturbed mean velocity data and enhanced spectrum widths. Important impacts on radar algorithms and radar decision making are: mis-identification of precipitation echoes, false estimates of precipitation, false mesocyclone signatures, incorrect storm cell identification, and incorrect VWP wind estimates.