Original 1st printing, 13 & 5/8x22" concert poster for Jack Bruce & Friends, Johnny Winter, Mountain, Eric Mercury, and Birthrite , at the Fillmore West in San Francisco, CA on 2/26-3/1/1970. 
 
Art by David Singer, image is #220 in the Bill Graham/Fillmore series. 
 
The poster is in excellent/very good condition.  There are some corner bends and light edgewear.  Otherwise nice.