Jump onto Googlemaps or Google Earth and go to the intersection of U.S. 95 and Hwy 54 in Athol, Idaho. Head west on Hwy 54 and you'll quickly cross BNSF, and then UP. Go north from Hwy 54 along BNSF and you'll see where the current two-tracked right of way continues in an almost northward direction, somewhat parallel to U.S. 95, while the abandoned NP grade curves off to the northwest just a half mile from Hwy 54. The grade snugs up real close alongside the UP (ex-SI) for almost a mile and a half.

Where the NP grade begins to arc back toward the northeast, you should be able to see two separate alignments, one protruding about a quarter mile further west with a more abrupt curve, and a later alignment which takes a more gradual arc. Eventually the NP grade swings back east and comes close to U.S. 95 at the Homestead Road crossing, and about three quarters of a mile later the grade enters a tunnel which was bypassed by an adjacent rock cut. The tunnel was still open when I first saw it in the 1980s, but it has since been buried shut at both ends. The NP grade continues northeast toward the bridge site, but the grade is gated shut and gets pretty treed-in before you reach the point where that 1200-foot long viaduct launched out across the tip of Granite Lake. The grade picks up on the northeast side of the ravine and angles back toward the existing BNSF tracks after passing through the tiny village of Granite.

You can drive most of the old NP grade around the big loop between the Homestead Road crossing and the north side of Athol. Quite a few homes out in that area. The piece of the grade from Homestead Road northeast toward the tunnel is kinda private property, and access to any of the grade between there and Granite is mostly on BNSF property. Not a good place to be without permission.

For the record, this line change was completed in September 1965. More than 2.5 million cubic yards of earth and gravel was excavated from the mile-long cut just north of Athol, plus more rock from the smaller cut near Granite, all of which went toward three major fills, the largest being the long, curved, 155-foot tall fill near Granite Lake. Now, if you want a real challenge, try following the original 1880s NP grade that looped to the east side of U.S. 95. It's easy to trace the first few miles northeast out of Athol on maps and in the field, but once it drops into the ravine, the grade has only a few cut and fill marks on the USGS topo and a few weathered pieces of roadbed on site to offer any clues.