Quotes from Northwest Waterfall Survey and various threads on Portland Hikers Forum:
Dalton Falls is - as far as we know - the only historically named ephemeral waterfall on the Oregon side of the Columbia Gorge. We've known about this waterfall's existence for dozens of years, hidden somewhere between Coopey and Mist Falls, but it wasn't until recently that we were clued in on its specific location. However, with further research and scouting it appears the waterfall which we originally thought was Dalton Falls may not actually be the real Dalton Falls. Our initial conclusion was that Dalton Falls occurs along the unmarked drainage one ravine west of Mist Creek, which is actually further east than we suspected it would be. However, given that this waterfall is highly seasonal and rather difficult to see from the Historic Columbia River Highway, it would seem an odd choice to give a name to. More recently Oregon waterfall hunter Zack Forsyth has explored the next perennial stream to the west and found it to harbor a significant waterfall that we now suspect may be the real Dalton Falls as the placement lines up with the maps which marked Dalton Falls as just east of Angels Rest. Until we do some further on-site investigation, this will remain an uncertainty.
It isn't known where the name came from, but it dates back to the early 1900's, and was likely named after the same individual whom nearby Dalton Point was named for.
Bryan Swan. Northwest Waterfall Survey. http://www.waterfallsnorthwest.com/nws/falls.php?num=3826
So the whole Dalton / Foxglove / Mesachie debate and numerous scouting runs into the area provided a lot of information, but frankly none of it convinced me that we'd identified with 100% certainty the real waterfall historically known as Dalton Falls. Now, with Google Earth's terrain model updated with LIDAR data throughout the Columbia Gorge, it provides a much easier method for field checking the various drainages without actually having to field check the various drainages. Once again, referring to the photo in the Arnato book:
Map reprinted from Annual Edition Portland Oregonian, January 1, 1915 : Sherman, Marty. Joyce Herbst. Kathy Johnson. Discovering Old Oregon Series: Volume 1 - Columbia River Gorge. 1984. Portland, OR: Frank Amato Publications. 6.
We see Dalton Falls immediately east of Angel's Rest, and markedly west of Mist Falls. In reality this gives us about 1.25 miles of the gorge to work with, but there's a ton of drainages in there. But then I noticed something else that was totally overlooked before: the cliff that runs along the road which is popular with climbers, right before crossing Mist Creek, is very clearly marked on this drawing. And Dalton Falls is significantly west of there. So with that now in mind, we have about 3/4 of a mile to work with, and can easily rule out the seasonal falls immediately west of Mist Falls as the real Dalton Falls, because that's the same stream which drops over the roadside climbing cliff.
The other thing that set me off tonight is how severely incised into the gorge this map shows Dalton Falls as being. Obviously the map isn't to scale, but does do a decent job of representing the actual structure of the cliffs in the area. So looking at both Foxglove and Mesachie Creeks, and where the waterfalls on those creeks lie - at around 1450' for Foxglove and 1600' for Mesatchie. The cliffs effectively stop above the 1600 foot mark, so one would assume that either of these falls would be depicted as falling from the top of the cliffs on such a meticulously drawn map. This makes me about 99% certain that none of the streams that have yet been explored harbor the actual Dalton Falls.
So the question then is where is it? Well, thanks to the LIDAR data in Google Earth, I think I located it. There's a small gully immediately east of Foxglove Creek - about a quarter mile as the bird flies - which doesn't look significant enough to harbor water, but take a look at the current satellite imagery and you'll notice a very distinct yet small slice of white streaming down the rock there. It's even more obvious when you look at it on Google Earth (lat/long: 45.56961, -122.14814) because you can zoom in further. The LIDAR rendering reveals a very distinct two-step cliff there, the upper about 80 feet and the lower about 200 feet, which seems to very nicely correspond with the hand drawn maps that existed back in the day. The location matches up, the incision within the cliffs looks right, and if the forest in there was logged out in the past it certainly would have been visible from the road. The odds of a spring-fed stream in there are quite good, given how many there are throughout the gorge, so the tiny size of the gully and drainage don't necessarily mean anything.
I don't know if there's any way to be 100% certain of this without finding a historical photograph, but to me this looks like the best bet of any of the proposed theories put forth so far.
Bryan Swan ("Sore Feet"). "Dalton - Foxglove conundrum!" Portland Hikers Forum. March 13, 2013. http://www.portlandhikers.org/forum/viewtopic.php?f=7&t=6696
[The Amato book] book is also single-handedly responsible for the identification of Dalton Falls, or at least pointing out the general area where it occurs and that it actually was named.
Bryan Swan ("Sore Feet"). "Upper Bridal Veil Falls" Portland Hikers Forum. December 20, 2010.http://www.portlandhikers.org/forum/viewtopic.php?f=10&t=6643&start=10
Here's another 1920s era map that shows Dalton Falls:
Tom Kloster ("Splintercat"). "Upper Bridal Veil Falls" Portland Hikers Forum. December 21, 2010. http://www.portlandhikers.org/forum/viewtopic.php?f=10&t=6643&start=10
1914 Oregonian article mentioning "Dalton Falls"
"Peabody". "Dalton - Foxglove conundrum!" Portland Hikers Forum. March 14, 2013. http://www.portlandhikers.org/forum/viewtopic.php?f=7&t=6696
...it looks like Dalton was the name for what we are now calling Foxglove. If this is the case it seems a bit of a shame to loose this History what do folks think? Maybe we should return to calling Foxglove Dalton & what we have been calling Dalton New Dalton!"Guy". "Dalton - Foxglove conundrum!" Portland Hikers Forum. December 22, 2010.http://www.portlandhikers.org/forum/viewtopic.php?f=7&t=6696
I'm fairly certain today's "foxglove" was Dalton Creek (and falls). Here's my theory on how such a seemingly obscure waterfall made its way onto a map celebrating the then new "historic highway."
At the time the highway was constructed, the region below Angel's Rest had basically been clear-cut. (Look at the trees there today - even the oldest is less than a hundred years old) This would have provided a direct view of the upper canyon where the falls are located.
The trees in the upper canyon are young as well, but for a different reason. The stream springs from dense red and grey clay (its an ashy volcanic layer responsible for many landslides in the Gorge). In the decade prior to the creation of the highway, I'm guessing there was a major slide that cleaned house, scouring the slopes lining the falls. This would have made the falls easily visible.
As they were building the highway, "Dalton Falls" would have been gawked at day in and day out. I'm guessing it was quite scenic. They would have been directly above Dalton Point State Park on the Columbia as well.
Today's "Dalton Falls" has caught on though...(as the falls near Mist Falls), while the original has slowly been overgrown. Nobody but waterfall enthusiasts (and apparently the residents who live on the stream's banks) know about it.
Given that, it might be confusing to switch the name back...but I'm certainly for it if others are. If not, Foxglove still works for me. It certainly is a an interesting piece of history!
Zach Forsyth ("chameleon"). "Dalton - Foxglove conundrum!" Portland Hikers Forum. December 22, 2010. http://www.portlandhikers.org/forum/viewtopic.php?f=7&t=6696
I don't think Foxglove was ever named as "Dalton" -- it's just not large enough, and is way above the old highway... and possibly a bit out of sight, as it faces west. You can clearly see it through the trees in my photos, so it's definitely where I located it on the maps -- which is far above the falls shown in the old Gorge sketch map.
I think Dalton is more likely one of the drops that can be seen to the east. It's also not impossible that a change in water table or some other geomorphology has reduced the flow to become seasonal over the past century -- that can happen, and so one of the gullies that Bryan points out could have had a larger/more consistent flow when the Dalton name was applied.
Tom Kloster ("Splintercat"). "Dalton - Foxglove conundrum!" Portland Hikers Forum. March 16, 2013. http://www.portlandhikers.org/forum/viewtopic.php?f=7&t=6696