Abstract: A lighting assembly can be quickly and efficiently mounted to a crown of a drilling rig derrick in order to provide wide-area illumination of the derrick and surrounding work location. An adjustable support frame member can be operationally attached to a hand rail of a derrick crown using fixed-length bracket members, adjustable-length bracket members and/or a combination(s) thereof. Lighting-emitting light source elements are adjustably attached to the support frame, and can be selectively aimed to direct light as desired.