P&W runs through Lake O on an "as needed" basis but infrequently. The Willamette Shores Trolley would have been your best bet, but it's shut down account trestle repairs.

Your best bet is: 1. Go west to Tualatin or Tigard (you can ride TriMet bus 78 which runs seven days a week, albeit 30-60 minute headways, to Tigard, or lines 36 or 37 to Tualatin P&R and transfer to 76 to the WES station) and watch WES go by. If you're lucky you may get a freight train or two; P&W does indeed run freight trains during the WES window, but traffic is generally down on the P&W and freight operations are hit and miss.

2. Go north to Portland and take in some urban railroading. Within a short walk/bike ride/TriMet ride from downtown Portland you can take in Union Station, Albina Yard, Brooklyn Yard, the UP Graham Line east out of Portland, the downtown MAX and Streetcar service, the Oregon Zoo's railroad.

3. Go east to Milwaukie; take in the Oregon Pacific RR and UP's Brooklyn Yard. The OPRR has a great collection of switchers and it's mostly viewable from public streets. If you have a bike, there is a very popular bike path that runs along the OPRR from Oaks Park up to OMSI and if you can catch a freight train you can railfan by bike in Portland. Or, continue east on the Springwater Trail and ride the old Portland Traction Company's mainline out to Boring. If you look carefully there's still a few reminders of its interurban/railroading past along the line.