Prescribed Burn 2-57 was the second of four prescribed burns studied in 1957. In this burn we were particularly interested in studying air flow on the lee side of a ridge oriented approximately at right angles to the prevailing wind. Experience has shown that erratic fire behavior frequently occurs under this situation. Instrumentation and observation methods were such that we could also further explore the techniques for determining local fireclimate patterns and relating these patterns to general weather. Fire behavior followed very closely the wind pattern indicated by the survey. A firewhirl developed in an area where vertical eddy circulation was found, and the fire crossed the fireline at a point where the survey indicated persistent cross-line winds.