I found a nice angle that captured the scene pretty well and Cam patiently waited while I setup the shot. As I took a few test frames, I noticed that the camera was picking up a bit of the light pollution in the sky from Bellingham, which looked orangy-red and had a nice contrast with the other colors in the scene. We couldn't even see this with our eyes, the sky just looked black.
I set up 3 flashes, one for the rock, and one on each side of where Cam would be in the shot to freeze him in the scene. I had him start about 200 feet away and opened the shutter. I yelled for him to look around slowly up at the trees with his helmet light so we could pick up some detail in the trees there, then had him ride down the trail. I closed the shutter right when he was at the ideal spot, and as I did, the rear-curtain flashes froze him as a bit of a ghost.
This shot was a 69-second exposure, which offered a nice amount of that orange sky for ambience. Pretty cool! I packed up my gear and we proceeded to have an awesome ride for 2 more hours. I never thought I would be the type to consider it normal to carry 30 lbs of photo gear on a 3 hour night ride just to setup for an additional hour to get a single photograph, but it was defnitely worth it. --Brad