The Overland Fire was discovered Wednesday morning in Lefthand Canyon near Boulder, Colorado. Hot dry winds have whipped the fire into a major blaze which is currently estimated at between 400 and 500 acres. Anyone interested in the complexities of running such an operation can listen to two of the Boulder County Sheriff's Office radio channels.
The red circle in the picture shows the spread of the smoke plume on Wednesday afternoon after the fire flared up to several hundred acres.
NCAR has a web cam that is taking in the view of the smoke north of Boulder.