CA 203

[Max Rockatansky]

That's the interesting part to this.  I knew there was conventional highway concepts for quite awhile.  I didn't realize until recently that this was part of the westward expansion of I-70.  Pretty much nothing I've ever read suggested this was the case overtly until I had a look at the file in the Caltrans Library.

[Voyager]

That's the interesting part to this.  I knew there was conventional highway concepts for quite awhile.  I didn't realize until recently that this was part of the westward expansion of I-70.  Pretty much nothing I've ever read suggested this was the case overtly until I had a look at the file in the Caltrans Library.

It almost sounds like it was a last ditch attempt to get a highway built after the Sierra Club got their way with stopping the traditional highway. I remember the Wikipedia article on it has something interesting that was the final nail in the coffin:

"Plans for a Trans-Sierra Highway connecting the Eastern Sierra and the San Joaquin Valley via Minaret Summit had been discussed since the early days of highway building.[3] The gap between Minaret Road, which runs northeast into the Sierra from North Fork, California, and the end of the Reds Meadow Road is less than 10 miles or 16 kilometres. An area southwest of Minaret Summit was not included in the Wilderness Act of 1964 in order to leave a corridor for this potential highway. While Governor of California, Ronald Reagan made a horse packing trip into the area. Afterwards he supported conservationists' efforts to prevent this highway. Reagan continued his efforts after being elected President in 1980 and the area was eventually designated wilderness by the California Wilderness Act of 1984.[3] The Sierra Nevada escarpment is now a continuous Wilderness from Ball Mountain (near Inyokern) to Tioga Pass, a distance of about 150 miles (240 km)."

https://en.wikipedia.org/wiki/Minaret_Summit

[Max Rockatansky]

Thing is though, the concept for a freeway died a natural death before 1970.  Even early conventional highway concepts had little support all the way back to the 1930s and even 1901.  The environmental resistance to the project in this case sure seems a totally secondary factor to the simple fact that the state didn't want to adopt a highway beyond Minaret Summit. Calling this an environmental win after the fact just doesn't line up with how everything played out.

[Voyager]

Thing is though, the concept for a freeway died a natural death before 1970.  Even early conventional highway concepts had little support all the way back to the 1930s and even 1901.  The environmental resistance to the project in this case sure seems a totally secondary factor to the simple fact that the state didn't want to adopt a highway beyond Minaret Summit. Calling this an environmental win after the fact just doesn't line up with how everything played out.

it is a shame though, considering the route goes down to 7,000 feet very quickly after Minaret Summit and from the looks of the terrain wouldn't need to go back up much over 8,000, once it gets past the Ritter Range, I'd think snow removal wouldn't be a very bad issue.

[cl94]

Yeah, from everything I have seen about Minaret, it really came down to "it would cost too much to build or maintain." With as much trouble as Caltrans has keeping Donner open, this would be over 2,000 feet higher with a substantial length of road over 6-7,000 feet. US 395 in the area routinely closes for extended periods in the winter. Sure, it would make it easier to get to the east slope, but anything over 8,000 in the Sierra is going to have major reliability issues.

And a freeway along the US 6 corridor in Nevada? That makes less sense than the proposals to build one along US 50. Even if another Sierra crossing is involved, there's just too much nothing in there. It would easily be the most remote stretch of the Interstate system outside of Alaska.

Thing is though, the concept for a freeway died a natural death before 1970.  Even early conventional highway concepts had little support all the way back to the 1930s and even 1901.  The environmental resistance to the project in this case sure seems a totally secondary factor to the simple fact that the state didn't want to adopt a highway beyond Minaret Summit. Calling this an environmental win after the fact just doesn't line up with how everything played out.

it is a shame though, considering the route goes down to 7,000 feet very quickly after Minaret Summit and from the looks of the terrain wouldn't need to go back up much over 8,000, once it gets past the Ritter Range, I'd think snow removal wouldn't be a very bad issue.

You'd be surprised. Again, look at the snow and drifting issues along 395. It would be another Snow Chi Minh Trail, except with much higher volumes of snow.

[Voyager]

Yeah, from everything I have seen about Minaret, it really came down to "it would cost too much to build or maintain." With as much trouble as Caltrans has keeping Donner open, this would be over 2,000 feet higher with a substantial length of road over 6-7,000 feet. US 395 in the area routinely closes for extended periods in the winter. Sure, it would make it easier to get to the east slope, but anything over 8,000 in the Sierra is going to have major reliability issues.

And a freeway along the US 6 corridor in Nevada? That makes less sense than the proposals to build one along US 50. Even if another Sierra crossing is involved, there's just too much nothing in there. It would easily be the most remote stretch of the Interstate system outside of Alaska.

Thing is though, the concept for a freeway died a natural death before 1970.  Even early conventional highway concepts had little support all the way back to the 1930s and even 1901.  The environmental resistance to the project in this case sure seems a totally secondary factor to the simple fact that the state didn't want to adopt a highway beyond Minaret Summit. Calling this an environmental win after the fact just doesn't line up with how everything played out.

it is a shame though, considering the route goes down to 7,000 feet very quickly after Minaret Summit and from the looks of the terrain wouldn't need to go back up much over 8,000, once it gets past the Ritter Range, I'd think snow removal wouldn't be a very bad issue.

You'd be surprised. Again, look at the snow and drifting issues along 395. It would be another Snow Chi Minh Trail, except with much higher volumes of snow.

I doubt it would have remained a year round pass, but I do wonder how early in the season it would get plowed/opened if it had been built (Sonora usually opens early to mid-May and Tioga is around late May to early June).

[Quillz]

It's really interesting to see the proposed alignment matched what I drew up some years ago. So I was pretty close with my guess. It also would have indirectly addressed the CA-168 gap, similar to how Sherman Pass Road unofficially makes CA-190 a trans-Sierra route.

However, my thoughts haven't really changed. Even ignoring all the environmental concerns, I'm just not sure what benefit you'd gain from this. It's not like it would be open any more often than the other trans-Sierra routes are. And then you're just dividing limited resources even further to keep it maintained. No doubt it would be pretty in the summer, but the only true benefit I can see is it would let people in the Bay Area reach Mammoth a bit easier. It wouldn't do much for SoCal, as most motorists utilize CA-14 and US-395.

I think this is another example of "we can do this, but should we do this?"

[cl94]

The "we can, but should we?" is why local governments generally preferred the Sonora Pass tunnel. That pass could realistically have a short-ish tunnel around 7,000 feet (base elevation on the east side) and, thanks to the canyons on both sides keeping things sheltered, it likely could have stayed open all year with little more expense than Echo or Donner. Such a tunnel would be far more useful than a high mountain road, especially because it would have connected to high-quality roads on both ends and made a good route across the mountains.

[Voyager]

The "we can, but should we?" is why local governments generally preferred the Sonora Pass tunnel. That pass could realistically have a short-ish tunnel around 7,000 feet (base elevation on the east side) and, thanks to the canyons on both sides keeping things sheltered, it likely could have stayed open all year with little more expense than Echo or Donner. Such a tunnel would be far more useful than a high mountain road, especially because it would have connected to high-quality roads on both ends and made a good route across the mountains.

Does the tunnel plan explain why they seem to have tried building 108 to expressway/freeway standards all the way to Strawberry? I always wondered why they had an expressway to Pinecrest (not exactly a busy resort/ski area).

[Max Rockatansky]

I can certainly see a purpose for a Forest Service Road connecting the end of Mammoth Pool Road to Minaret Summit (a surprisingly small gap).  I would be lying if I didn't say my thought process wasn't influenced by the erratic on/off stance of Yosemite National Park requiring reservations for the Tioga Pass Road. To me a gravel grade would be just fine and would be in step with the great Sierra Vista Scenic Byway.

Regarding Sonora Pass I think the intent was always to improve that whole corridor to an expressway.  The tunnel concept seems to have never really advanced very far.

[Voyager]

I can certainly see a purpose for a Forest Service Road connecting the end of Mammoth Pool Road to Minaret Summit (a surprisingly small gap).  I would be lying if I didn't say my thought process wasn't influenced by the erratic on/off stance of Yosemite National Park requiring reservations for the Tioga Pass Road. To me a gravel grade would be just fine and would be in step with the great Sierra Vista Scenic Byway.

Regarding Sonora Pass I think the intent was always to improve that whole corridor to an expressway.  The tunnel concept seems to have never really advanced very far.

I read that it's only about a 5-8 mile gap between the end of the furthest forest service road branch in that area to Reds Meadow Road at its end?

[Max Rockatansky]

I can certainly see a purpose for a Forest Service Road connecting the end of Mammoth Pool Road to Minaret Summit (a surprisingly small gap).  I would be lying if I didn't say my thought process wasn't influenced by the erratic on/off stance of Yosemite National Park requiring reservations for the Tioga Pass Road. To me a gravel grade would be just fine and would be in step with the great Sierra Vista Scenic Byway.

Regarding Sonora Pass I think the intent was always to improve that whole corridor to an expressway.  The tunnel concept seems to have never really advanced very far.

I read that it's only about a 5-8 mile gap between the end of the furthest forest service road branch in that area to Reds Meadow Road at its end?

Yes, it is literally that short as the bird flies now from Squaw Dome.

[andy3175]

That's the interesting part to this.  I knew there was conventional highway concepts for quite awhile.  I didn't realize until recently that this was part of the westward expansion of I-70.  Pretty much nothing I've ever read suggested this was the case overtly until I had a look at the file in the Caltrans Library.

This is a very good find. Until now, I had only known there was a planned routing of westward extension of I-70 over the Sierra but could not locate documentation that conclusively demonstrates it was studied. And it rightfully got the "no build" treatment, which is wise considering the location ... tons of snowfall, ample scenery, and extensive mountains. Even if the grades were made gentler, the generous amount of snow that occurs annually at Mammoth would made this freeway very difficult to maintain in the winter. Until seeing the excerpts you had found, I was under the impression any routing of I-70 would be further north, perhaps along SR 88 or even US 50 (even though I had no proof of that from any formal study). Thank you for sharing!

[Max Rockatansky]

That's the interesting part to this.  I knew there was conventional highway concepts for quite awhile.  I didn't realize until recently that this was part of the westward expansion of I-70.  Pretty much nothing I've ever read suggested this was the case overtly until I had a look at the file in the Caltrans Library.

This is a very good find. Until now, I had only known there was a planned routing of westward extension of I-70 over the Sierra but could not locate documentation that conclusively demonstrates it was studied. And it rightfully got the "no build" treatment, which is wise considering the location ... tons of snowfall, ample scenery, and extensive mountains. Even if the grades were made gentler, the generous amount of snow that occurs annually at Mammoth would made this freeway very difficult to maintain in the winter. Until seeing the excerpts you had found, I was under the impression any routing of I-70 would be further north, perhaps along SR 88 or even US 50 (even though I had no proof of that from any formal study). Thank you for sharing!

US 50 was conceptually explored as part of the 1973 Federal Aid Highway Act.  Adam will eventually have something on that for our page as he found a bunch of documents regarding it.

[andy3175]

US 50 was conceptually explored as part of the 1973 Federal Aid Highway Act.  Adam will eventually have something on that for our page as he found a bunch of documents regarding it.

That's right! I had forgotten about that but had encountered the freeway proposal when I was researching Lake Tahoe-area roads. I'll look forward to the update on your site. I am glad you're taking the time to research these things, as I just don't have the time as I used to. Thanks.

[pderocco]

This idea of a Sonora Pass Tunnel is one that I had never heard of. But if the idea was to build it at around 7000 feet, it looks to me like it would need to be over ten miles long, not seven. And this is four times longer than any other road tunnel in the country\. And most people would prefer to see the sights going over the mountains, not to spend ten minutes in claustrophobic darkness. Besides, it's too far north. Something closer to the middle of the vast uncrossable part of the Sierra Nevada would be more useful.

[cl94]

9 miles (the approximate distance required from the base on the east side) is totally feasible and was about the same length as the longest road tunnel that existed in the late 70s.

The biggest problem with anything further south is that any pass would be higher, any tunnel longer, and any tunnel would pass through a portion of the Sierra with far more tectonic and volcanic activity. A tunnel in the Mammoth area is not feasible because Mammoth Mountain itself and the surrounding region have high levels of volcanic activity. Something in the Kings Canyon area may be feasible under modern standards, but the national park exists to stop construction of a road across the Sierra.

US 50 was conceptually explored as part of the 1973 Federal Aid Highway Act.  Adam will eventually have something on that for our page as he found a bunch of documents regarding it.

That's right! I had forgotten about that but had encountered the freeway proposal when I was researching Lake Tahoe-area roads. I'll look forward to the update on your site. I am glad you're taking the time to research these things, as I just don't have the time as I used to. Thanks.

And by the time it was explored for federal funding, it was DOA because of Tahoe protections. California would have needed to get shovels in the ground by the mid-1960s to have any shot at getting it built.

(personal opinion emphasized)

[Max Rockatansky]

Even the US 50 freeway alignment adoption included a tunnel through Echo Summit.  Echo Summit and Sonora Pass at minimum were a considerable distance north of the Kern Canyon Fault (irony being that moved last week around Caliente-Bodfish Road).

[heynow415]

9 miles (the approximate distance required from the base on the east side) is totally feasible and was about the same length as the longest road tunnel that existed in the late 70s.

The biggest problem with anything further south is that any pass would be higher, any tunnel longer, and any tunnel would pass through a portion of the Sierra with far more tectonic and volcanic activity. A tunnel in the Mammoth area is not feasible because Mammoth Mountain itself and the surrounding region have high levels of volcanic activity. Something in the Kings Canyon area may be feasible under modern standards, but the national park exists to stop construction of a road across the Sierra.

US 50 was conceptually explored as part of the 1973 Federal Aid Highway Act.  Adam will eventually have something on that for our page as he found a bunch of documents regarding it.

That's right! I had forgotten about that but had encountered the freeway proposal when I was researching Lake Tahoe-area roads. I'll look forward to the update on your site. I am glad you're taking the time to research these things, as I just don't have the time as I used to. Thanks.

And by the time it was explored for federal funding, it was DOA because of Tahoe protections. California would have needed to get shovels in the ground by the mid-1960s to have any shot at getting it built.

(personal opinion emphasized)

Another advantage of a 108/Sonora Pass tunnel alignment for an I-70 extension is that it would have lined up nicely with passing just south of Stockton (and the Port of) and then as an east/southeast entry to the Bay Area via the Altamont Pass/I-580/I-205/SR 120.   

[pderocco]

9 miles (the approximate distance required from the base on the east side) is totally feasible and was about the same length as the longest road tunnel that existed in the late 70s.

What tunnel was that? Something in the Alps?

[cl94]

What tunnel was that? Something in the Alps?

Arlberg and Gotthard are both from that period. Construction of both started in the early 70s, both opened late 70s-1980. Now, Europe is much more willing to build long tunnels than we are, but that length isn't a real problem.

[Voyager]

9 miles (the approximate distance required from the base on the east side) is totally feasible and was about the same length as the longest road tunnel that existed in the late 70s.

The biggest problem with anything further south is that any pass would be higher, any tunnel longer, and any tunnel would pass through a portion of the Sierra with far more tectonic and volcanic activity. A tunnel in the Mammoth area is not feasible because Mammoth Mountain itself and the surrounding region have high levels of volcanic activity. Something in the Kings Canyon area may be feasible under modern standards, but the national park exists to stop construction of a road across the Sierra.

US 50 was conceptually explored as part of the 1973 Federal Aid Highway Act.  Adam will eventually have something on that for our page as he found a bunch of documents regarding it.

That's right! I had forgotten about that but had encountered the freeway proposal when I was researching Lake Tahoe-area roads. I'll look forward to the update on your site. I am glad you're taking the time to research these things, as I just don't have the time as I used to. Thanks.

And by the time it was explored for federal funding, it was DOA because of Tahoe protections. California would have needed to get shovels in the ground by the mid-1960s to have any shot at getting it built.

(personal opinion emphasized)

Another advantage of a 108/Sonora Pass tunnel alignment for an I-70 extension is that it would have lined up nicely with passing just south of Stockton (and the Port of) and then as an east/southeast entry to the Bay Area via the Altamont Pass/I-580/I-205/SR 120.   

I always thought it was strange how 108/120 are basically freeways up to the Sonora area and then 108 has sections that keep going as random freeway and expressway in the mountains for it to just go straight into a windy road after Strawberry and Pinecrest Lake.

[Max Rockatansky]

I believe both were intended to be freeway/expressway all the way to the crest of the Sierra Nevada range.  Stuff like the freeway alignment which was intended to replace the Priest Grade were wild to read about in the CHPWs.

[heynow415]

Another advantage of a 108/Sonora Pass tunnel alignment for an I-70 extension is that it would have lined up nicely with passing just south of Stockton (and the Port of) and then as an east/southeast entry to the Bay Area via the Altamont Pass/I-580/I-205/SR 120. 

I always thought it was strange how 108/120 are basically freeways up to the Sonora area and then 108 has sections that keep going as random freeway and expressway in the mountains for it to just go straight into a windy road after Strawberry and Pinecrest Lake.

The Sonora "freeway" section is relatively new in the grand scheme of things but the three short expressway segments east of Knights Landing, through Twain Harte, and at Long Barn have been in place 50+ years.  It is unfortunate that the notion of extending 120 east of 99 as a freeway to Oakdale is basically dead, though Escalon and Oakdale are probably rightly concerned that a freeway bypassing those communities would be a huge hit to them economically.

Four-laning 108(120) from the east end of the Knights Ferry segment to Yosemite Junction would seem like a relatively simple project given the ruralness and terrain; getting from the Junction through Jamestown to the Sonora segment would be a much bigger challenge.  The section from the east end of the Sonora segment to the Twain Harte expressway is supposedly in the works.  It's unlikely that the gap from Twain Harte to Long Barn would ever be built since trying to thread it through Mi-Wuk Village and other hamlets along the way, plus the terrain, is likely not justifiable from a cost, environmental, and constructability standpoint.  And beyond Pinecrest it just isn't needed.

[Voyager]

Another advantage of a 108/Sonora Pass tunnel alignment for an I-70 extension is that it would have lined up nicely with passing just south of Stockton (and the Port of) and then as an east/southeast entry to the Bay Area via the Altamont Pass/I-580/I-205/SR 120. 

I always thought it was strange how 108/120 are basically freeways up to the Sonora area and then 108 has sections that keep going as random freeway and expressway in the mountains for it to just go straight into a windy road after Strawberry and Pinecrest Lake.

The Sonora "freeway" section is relatively new in the grand scheme of things but the three short expressway segments east of Knights Landing, through Twain Harte, and at Long Barn have been in place 50+ years.  It is unfortunate that the notion of extending 120 east of 99 as a freeway to Oakdale is basically dead, though Escalon and Oakdale are probably rightly concerned that a freeway bypassing those communities would be a huge hit to them economically.

Four-laning 108(120) from the east end of the Knights Ferry segment to Yosemite Junction would seem like a relatively simple project given the ruralness and terrain; getting from the Junction through Jamestown to the Sonora segment would be a much bigger challenge.  The section from the east end of the Sonora segment to the Twain Harte expressway is supposedly in the works.  It's unlikely that the gap from Twain Harte to Long Barn would ever be built since trying to thread it through Mi-Wuk Village and other hamlets along the way, plus the terrain, is likely not justifiable from a cost, environmental, and constructability standpoint.  And beyond Pinecrest it just isn't needed.

They are making 108/120 a freeway to Oakdale (eventually)

https://northcountycorridorphase1.com/project-overview/#:~:text=The%20ultimate%20North%20County%20Corridor,was%20segmented%20into%20four%20phases.