I'm not sure how easy it is to bike the grade in that area. I remember there being areas still layered in ballast. Perhaps it's been scooped and taken elsewhere. You wanna bike some SP&S and other grades with ease, AND see some trains? Go up to Cheney, ride the paved portion of the trail north of Fish Lake, passing under the UP bridge and then the BNSF bridge. Easy enough to pedal back uphill to Cheney. Then drive to the trailhead at Scribner, where you ride a paved segment of the former UP/MILW grade all the way into Spokane, with BNSF trains on the SP&S and NP lines on either side of you. Stop at Gatto's Pizza in Cheney and get a booth with a window view of the railroads. Hopefully EWG won't have power or cars parked on the near track.