not every airport/runway has marker beacons. not all approaches use them. the markers aren't a part of the approach you referenced. the FAF is the PORCY waypoint, which only your GPS will identify.
(there are no marker beacons out at shelton. for fun, try the NDB approach
http://naco.faa.gov/d-tpp/0801/06643NGA.PDF with only an ADF needle and a strong crosswind)
on a GPS approach, you need to scan your instruments AND the gps AND look out the window. oh, and starting the timer wouldn't hurt either, just in case the GPS konks out on ya.