Jim, I'd have to add a comment about the SP&S/GN verses the NP. The NP was built much earlier than the SP&S and was built by hand. (As you know.) The technology just 20+ years later allowed the SP&S (and the Milwaukee) to be built with much better grading. In Montana the NP compares poorly to the parallel Milwaukee between St. Regis and Missoula. But the NP was merely the Wallace branch upgraded to mainline after the cutoff was built between St. Regis and Paradise in 1908. The cutoff a superbly graded line, most of it 60mph. (Which I'm guessing you've tested on the 700.)

Between Missoula and Garrison the NP was a winding line that followed the river on a low grade. After the floods of 1908 and concurrent with the grading of the new Milwaukee it became 70 miles of well graded double track. The BN had a 75 mph speed limit for passenger and today MRL allows freights 60 mph on most of it. The "slow" curves are mostly 55 or 50 mph with only one 45 limit for a mile in the middle (and a little 45 at Garrison). When the NP was built with picks and shovels and wheel barrows it was indeed a poorly graded line but any place they rebuilt in later years was top notch.

The GN across northern MT is known for it's roller coaster profile and is a challenge to engineers. To smooth out the long rolling hills would have cost a fortune and trains that are powered up for Marias Pass have plenty of power to pull these hills so it's not an issue. Especially now that there are no cabooses.

I don't know the politics involving the decisions to build the SP&S's amazing grade between Pasco and Spokane or which parent had sway over such decisions but the fact that the NP would pony up 50% of the cost of a direct competitor speaks volumes. Instead of insisting the GN build it's own line to Pasco (from Spokane) to connect with a joint NP/GN (SP&S) line to Portland the NP supported the eastern end of the SP&S. I can only surmise that this was NP's way of enjoying (through trackage rights) a line that was better graded and could provide a double mainline for NP. If you consider the double track and the two mainlines NP (along with SP&S) had two main tracks between the coast and Livingston with the exception of Spokane to Paradise and Bozeman Tunnel. Along with many other segments of true double track (Billings-Laurel, Seattle to Portland, Minnesota) it indicates a desire to upgrade the NP as much as possible. I'd say that the NP did it's best to overcome a railroad graded in the 1880's and worked hard to mitigate that over the years.

When the BN was formed the NP was considered to be "over-engineered" and I see what they were saying. NP had poored a lot of money into track upgrades and in the end I don't think the traffic supported the infrastructure. Of course now they need it all and more but we're talking about NP and early BN.

While I agree that the original NP was built on a rough grade I do think your comments needed more explanation.

An interesting side note is that the Helena (MT) railroaders called the ex-GN line (Helena--Great Falls) the "turkey trail" and the ex-NP mainline though Helena was a well built and maintained track.

By the way, I have long had a soft spot for the SP&S and have seen it from freights, passenger trains and my boots a number of times since shortly after the merger. I think the old 3rd sub should have been kept in service and either the "Panama track" revamped at Pasco or the proposed downriver SP&S bridge built to provide a better connection for through trains on the former SP&S. But they didn't ask me.