Odor samples were collected two to four times per month over a one-year period in 2002-2003 at three large open-lot beef cattle feedyards in the Texas panhandle. Samples were collected in 10 L Tedlar bags using a vacuum chamber upwind of the feedyard, downwind of the pens, and downwind of the runoff storage pond. Samples were analyzed in the odor lab for detection threshold (DT) using triangular forced choice olfactometry with trained human odor panelists. Full-strength odor samples were also analyzed for intensity and hedonic tone. Weather data was collected on-site at each of the feedyards for correlation to odor characteristics. At two of the feedyards, mean upwind DTs were similar to DTs downwind of the pens and storage pond, ranging from 33 to 45. At the third feedyard, the mean upwind DT was 36, compared to 68 downwind of the pens and 124 downwind of the pond. Results of the research indicate that DT alone may not be a good indicator of odor characteristics and offensiveness from beef cattle feedyards.