There are at least three bands and a DJ known as "Steam":
These are photos from concerts where Steam played, so they may be of other bands that played the concert as well.
Steppenwolf / Pacific Gas & Electric / Steam / In-Sex Apr 3, 1970 Philadelphia, Pennsylvania, United States Uploaded by Zimtrim
St. Valentine's Pop Festival Feb 14, 1970 Clemson, South Carolina, United States Uploaded by Zimtrim