An experimental investigation illustrating some separated flow phenomena associated with highly inclined circular cones was conducted at a nominal Mach number of 5 and at nominal free stream Reynolds numbers per foot of 4,800,000. Surface static pressure measurements, Pitot pressure surveys, schlieren photographs, vapor screen photographs, and surface sublimation measurements were obtained on a sharp 5 degree semi-vertex angle cone at angles of attack up to 40 degrees. The static pressure distribution along the most leeward meridian generator was found to be dependent upon the Reynolds number based upon the distance from the vertex of the cone. The vapor screen photographs at 40 degrees angle of attack indicate the existence of imbedded shock waves in the flow field on the leeward side of the cone. The Pitot tube surveys and the surface sublimation photographs indicate the existence of a region of attached flow near the leeward meridian plane. The surface sublimation photographs also indicate the possible existence of a secondary vortex. (Author).