I feel perfectly safe. During my night rides I have encountered one police car (the driver did not stop), three security guards, about four night-shift employees, and less than a dozen bicyclists. Yes, this Green River is the same one. Gary Ridgway, the Green River Killer, has been in prison for years and will be until he dies, and there has not been any copycat activity. I have probably ridden past two or three sites where bodies were found. More info on the Green River Killer: https://en.wikipedia.org/wiki/Gary_Ridgway .
Dave, I am wondering if riding around late at night near the Green River area is 100% safe. Is that the same Green River where a famous murderer used to hang about. People have very long memory's. A few months ago I was questioned by two detectives for acting suspiciously. I was walking along the rivers edge at low tide taking photographs in the middle of the day. Hundreds of yards away from any property. They said they had been phoned by a few people. The only good thing about the incident was the detectives had to walk a long way over muddy ground to get to me. They were not very happy about the state of their shoes.