I'm not sure where you're drawing the line between early and mid 70s or where you were at the time but in 1972 I was running in the Tiger Cortez/Corsair. I got them at Schenk and Title's in Harrisburg, Pa. At the Olympic Trials Marathon that year Nike was giving free shoes to everyone in the race. Mark Covert became the first runner ever to finish a race in Nike shoes when he came seventh in the marathon trial. Later that summer I ran a one hour run on the track at West Virginia University. Carl Hatfield had run the Trials Marathon and was at that race. He was showing us the Nikes he'd brought back from Eugene. I think of '72 as early 70s. But if you are talking 1971 or earlier I'd agree that in many places your only choices were adidas or Puma, and in some places not even those two, though even then I think Tiger was turning up here and there.