Start and End Points for Washington Mountain Passes

[Amaury]

So, before I joined here, I did not understand why some routes were signed with two or more other route numbers, such as I-82 also having signs for US 97 and US 12. My mom thought it was just because certain routes, such as I-82, also led you to those other routes, which is partially true, but that's not why. Now I know that they're concurrent routes that share the same roadway rather than there being a gap in, for example, US 97 one some occasions. That's also why I say partially true, since they don't necessarily "lead" you there, as you're already on there as part of a concurrency.

Now, to the main point of this thread. I also used to think that passes were only the summits, such as Snoqualmie Pass only being at its summit, but I later learned through my mom and other places that the pass is also the whole way up to the summit from the lowest point and the whole way down from the summit to the lowest point, not just the summit itself. The lowest point I guess would be at sea level, but not entirely sure on that. Not including the signs already at the summits with the pass names and elevations, I know some passes, such as Stevens Pass, also have signs at certain points showing you how many feet above sea level you are.

For the most part, through watching YouTube videos of people showcasing the passes here in my home state of Washington and my own experiences, I've figured out where almost each pass starts and ends.

In alphabetical order:

• Blewett Pass is the stretch of US 97 between the junction with SR 970 and the WSDOT maintenance facility at milepost 178
• Chinook Pass is the stretch of SR 410 between the junction with SR 123 and the Hells Crossing Campground near milepost 84
• Manastash Ridge, North Umtanum Ridge, and South Umtanum Ridge are the stretch of I-82 between milepost 1 and roughly mile 27.5
• Washington Pass and Rainy Pass are the stretch of SR 20 between milepost 148 and milepost 178
• Satus Pass is the stretch of US 97 between the junction with SR 142 and roughly mile 34.5
• Sherman Pass is the stretch of SR 20 between the eastern junction with SR 21 at milepost 305 and the junction with US 395
• Snoqualmie Pass is the stretch of I-90 between milepost 19 and milepost 62
• Stevens Pass is the stretch of US 2 between milepost 57 and milepost 80
• Wauconda Pass is the stretch of SR 20 between the junction with US 97 and milepost 302 in Republic
• White Pass is the stretch of US 12 between milepost 130 in Packwood and milepost 160

Those are the main ones listed on WSDOT. There are some others, such as Alpowa, but I'm not listing those. From the WSDOT page, there are three I still cannot fully figure out: Cayuse Pass (SR 123), Disautel Pass (SR 155), and Loup Loup Pass (SR 20).

• Where is the northbound starting point/southbound ending point and northbound ending point/southbound starting point for Cayuse Pass?
• Where is the northbound starting point/southbound ending point and northbound ending point/southbound starting point for Disautel Pass?
• Where is the eastbound starting point/westbound ending point and eastbound ending point/westbound starting point for Loup Loup Pass?

For Loup Loup Pass, I want to say the eastbound starting point/westbound ending point is the junction with SR 153, but I'm not sure, and I don't really know where the eastbound ending point/westbound starting point is. Cayuse Pass is further confusing me because the WSDOT page says it is carried by SR 123, while the Wikipedia page says it is carried by SR 410. I know the WSDOT is the official page, but where is Wikipedia getting SR 410 from? And where is the lowest point for each direction (northbound and southbound)?

I know these seem like trivial questions, but since I became a heavy road and sign geek after joining here, I'm curious now.

[pderocco]

Just looking at Snoqualmie, the one I'm most familiar with, I don't see the significance of mile 19 at about 500 feet, and 62 at about 2400. So what are you basing these beginnings and endings on?

I've always thought of a pass as referring to the high point, not the entire road. Geographically, it's usually a saddle. The high points are often signed with an elevation, but are often named differently. I-80 has Donner Summit, I-5 has Tejon Pass (and Siskiyou Mtn. Summit on southern Oregon), I-15 has Cajon Summit but no signage over Mountain Pass, and I-8 has Tecate Divide. There is also a Sherman Pass Rd going over the Sierra Nevada, but that refers to the well-defined road, not the pass itself, and the sign at the top only says Elevation 9200.

So I don't think these things are ever named very consistently.

Besides, I always though of a summit as a mountain peak, and thought it odd that passes would be labeled as summits.

[gonealookin]

I don't think these things are ever named very consistently.

Besides, I always though of a summit as a mountain peak, and thought it odd that passes would be labeled as summits.

In common usage I don't think "pass" ever refers to the entirety of the road from the commencement of a climb in one valley to the end of a descent in the next valley.  It's more the immediate saddle area where the road reaches its highest point, and the "summit" would be the high point within that saddle.

In the local vernacular, on Nevada SR 207 one drives up Kingsbury Grade from either US 50 at Lake Tahoe or SR 206 on the western edge of the Carson Valley.  The crossing of the Carson Range happens at Daggett Pass.  There's a sign up there that says "Daggett Summit, Elev. 7334", but NDOT is alone in calling it Daggett Summit.  In a newspaper article it's likely Daggett Pass, and in conversation, probably "the top of Kingsbury".

[Max Rockatansky]

Just occurred to me that your user avatar was from Phantasy Star IV.  Talk about a throwback to when my Sega Genesis was new.

[Amaury]

Just looking at Snoqualmie, the one I'm most familiar with, I don't see the significance of mile 19 at about 500 feet, and 62 at about 2400. So what are you basing these beginnings and endings on?

For Snoqualmie Pass, there was a video like this one, which showcases Ryegrass and the summit: https://www.youtube.com/watch?v=hkRd3dwZyJI

It was from a different user, and it ran from about milepost 19 to about milepost 62, which, if heading eastbound, is just after you pass under the wildlife crossing. Throughout the video, it showed the elevation levels, which aren't actually posted, but the user figured them out. The same user who did Snoqualmie Pass also did Chinook Pass. Unfortunately, I cannot find those videos, and I don't remember the name of the user. If I find them again, I'll post them.

What further confuses me is that passes like Chinook Pass and Cayuse Pass don't even have a sign anywhere saying the name of the pass and its elevation. I don't know if it ever had one heading westbound, but Snoqualmie Pass had one eastbound, which has needed repairs for a few years now, and has yet to be repaired: https://maps.app.goo.gl/3qbBhHb9nF1GrwhJ9

That's just past Exit 52. The capture is from August 2019. Sometime after that is when the sign fell.

Passes like Blewett Pass are the ones I kind of just guessed on my own. I use the SR 970 junction as the northbound start point/southbound end point because that's where the electronic reader board is with warnings such as "Chains Required All Vehicles Except AWD" during the winter, and those boards are always placed before you get to a section of road that's prone to extra bad conditions in the winter: https://maps.app.goo.gl/R6cFS95xqr4K9QuD8

Same thing for the southbound start point/northbound end point just past the WSDOT maintenance facility at milepost 178. There's an electronic reader board there for southbound traffic: https://maps.app.goo.gl/Z7yw725q2sYnjbqc9

[Amaury]

In common usage I don't think "pass" ever refers to the entirety of the road from the commencement of a climb in one valley to the end of a descent in the next valley.  It's more the immediate saddle area where the road reaches its highest point, and the "summit" would be the high point within that saddle.

In the local vernacular, on Nevada SR 207 one drives up Kingsbury Grade from either US 50 at Lake Tahoe or SR 206 on the western edge of the Carson Valley.  The crossing of the Carson Range happens at Daggett Pass.  There's a sign up there that says "Daggett Summit, Elev. 7334", but NDOT is alone in calling it Daggett Summit.  In a newspaper article it's likely Daggett Pass, and in conversation, probably "the top of Kingsbury".

I don't know about newspapers, but Deadman Pass on I-84 in Oregon might be a good example of this, which seems to run from milepost 214 near Pendleton to milepost 260 near La Grande, or vice-versa, from videos I've seen of people showcasing it. (Some people refer to it as Cabbage Hill.) The difference here is that the summit has a different name than the pass, being called Blue Mountains Summit. Blue Mountains Summit is the also the name of the summit on Oregon 204, but I think they might be the same mountain, so I guess that makes sense. Then there's a pass on US 95 in Oregon called Blue Mountain Pass. Notice the no "S." I wouldn't blame people if they got confused or mixed up, with so many summits/passes with Blue Mountain(s) in it.

As for the saddle point, if that is the case, would there be an easy way to figure that out for each pass or whatever the state calls it (pass, ridge, crest, etc.)?

[pderocco]

I don't know about newspapers, but Deadman Pass on I-84 in Oregon might be a good example of this, which seems to run from milepost 214 near Pendleton to milepost 260 near La Grande, or vice-versa, from videos I've seen of people showcasing it. (Some people refer to it as Cabbage Hill.) The difference here is that the summit has a different name than the pass, being called Blue Mountains Summit. Blue Mountains Summit is the also the name of the summit on Oregon 204, but I think they might be the same mountain, so I guess that makes sense. Then there's a pass on US 95 in Oregon called Blue Mountain Pass. Notice the no "S." I wouldn't blame people if they got confused or mixed up, with so many summits/passes with Blue Mountain(s) in it.

When you look at that point on I-85, it doesn't really look like a "pass" because there aren't much higher mountains or hills on either side. It's just a reasonable spot to pick to cross this hilly area. In fact, when I drove over that last year, I didn't really have the sense that I was going "over the mountains", perhaps because the east side isn't as dramatic grade as Emigrant Hill.