For those of you who have Lisa Foster's excellent guide Rocky Mountain National Park - The Complete Hiking Guide, note the following error on page 55. The map shows the trail to Shelf Lake on the south side of Shelf Creek. The trail is actually on the north side of the creek.
Foster's description on page 54 is correct, as is brenta's here on SP.
Yes, I was at Shelf Lake on Saturday with Aaron and Ellen. The rest of their hiking group bailed out on the Pagoda climb. They must have heard "that Nelson guy" was tagging along.
Shelf was one of the most spectactular places I have ever been in RMNP. It requires many return visits. The weather was not cooperating so we didn't get past the lake itself, but the Arrowhead and Thatchtop now await ascents from there. I also wouldn't mind being there are crack of dawn for photography.