Original 1st printing 23&1/8 x 29" untrimmed printer's proof sheet (poster and (4) handbills) for the 7/8/1979 San Francisco Marathon, held at the Polo Fields in Golden Gate Park.
  
Art by David Singer (printed by Tea Lautrec) medium-thick glossy-coated stock poster is in near mint (A- to A-/B+) condition; really nothing more than a few stray fingerprint smudges/nearly-invisible handling dings here and there and a couple of minor creases in the lower left corner, otherwise it is a SUPERB example of this uncommon late-'70's David Singer item from one of the very first SF marathons.