Conversation so far:
what was snake river canyon in regards to evel knievel ?
The launch took place at the south rim of the Snake River Canyon.
what was the launch of?
Knievel hired subcontractor and aeronautical engineer Doug Malewicki to build him a rocket-powered cycle to jump across the Snake River.
when was the launch?
on Sunday, September 8, 1974, at 3:36 p.m.
MDT.

Question: how many people watched?
Self-contained rewrite: how many people watched Evel Knievel at snake river?