I've followed the case since day one. .
The killer had, obviously, a familiarity with the trail prior to the abduction (late summer/fall?), plus IMO he may have considered other trails. He knew where to hide a vehicle, knew trail access points, knew where to corner victims, knew where to conceal bodies, had weapons, dressed in an extra layer, knew there was no school, and, presumably, had an escape route. It was late winter in Delphi, usually snow on the ground but not then. Probably not a lot of people on the trail... an opportunity... IMO he planned this well and planned it in advance.
He could be hiding in plain sight. Someone's brother, father, uncle, husband... not from the area... A reward would not bring results if people haven't put two and two together. Remember the Green River Killer and BTK living in mainstream society? The public needs one more clue - a weapons description.
The one thing that makes me think the killer lured the girls is the photo. Why would LG take a photo of a stranger? Just doesn't seem logical...
As to the sketch, I am skeptical because it was made weeks after the fact. Witnesses aren't always accurate, and who's to say this person's sketch was connected to the killer? Not a local with that hat, which would totally stand out in the Midwest where baseball type caps are the norm.