Map symbol ID question...

[Daistallia]

A cousin who does anthropology had a question that someone here may be able to answer about a symbol on an old USGS map.

This is a detail of the 1922 USGS Forest 15' quad, showing Highway 489 with red dots along it. Has anyone seen this symbol and know what it means? I think it might mean under construction, but that's a guess...

USFS.jpg
usfs 2.jpg

Anybody know for sure if that's correct?

[Shenanigans]

Well this piqued my curiosity, so I went digging! I didn't find a specific explanation, but I did find similar maps that use black/red dots along roads to indicate points of interest, such as property entrances. On those maps, the red dots also have photography of the location. There might be a collection of corresponding photographs to go with the map. I also checked Google Maps, and many of these locations match up with unused easement roads. Basically, driveways that go nowhere, but are marked out for future use if the land is ever developed. They are often spaced at regular intervals. My best guess is that they're property entrances from the original survey.

I don't think it means under construction. I think that's usually a dashed double line.

[Daistallia]

On those maps, the red dots also have photography of the location. There might be a collection of corresponding photographs to go with the map.

Very doubtful. Remember this is a 1922 USGS quad.

I also checked Google Maps, and many of these locations match up with unused easement roads. Basically, driveways that go nowhere, but are marked out for future use if the land is ever developed. They are often spaced at regular intervals. My best guess is that they're property entrances from the original survey.

I don't think that's it. They'd be irregular, and the dots are regular.

I don't think it means under construction. I think that's usually a dashed double line.

Indeed. The question here is whether this is an old symbol/convention that's been superceded.

[Shenanigans]

I admit that the photos is a bit of a long shot, but it's not at all unreasonable. Surveying is a very thorough industry.

As for the roads, they are placed at very regular intervals on purpose. That's the entire point. They would not be irregular at all, because when you're out surveying in the field you need to know where they are so that you can access a property without driving through a 3 foot ditch.

It's possible that the symbology for road construction was changed, so I referenced the 1849 manual from the Department of the Interior, and they use a double dashed line for road construction. Seeing as this map has double dashed roads on it, I doubt they changed it, because that would just make things really confusing.

Most interestingly, though, I went and downloaded a copy of the map to see if it had a legend, and the dots are completely absent. They might have been added by a person using the map, or been specific to that version of the map, but whatever they represent, I don't think it's part of their official notation.

Edit: I found a symbology guide from closer to the period, and it looks like they changed double dash to unimproved, and under construction to thick red dashes. So there was a minor change there.

[Shenanigans]

Hmm... the more I look at this, the more it looks like someone drew their own markers on an existing map. They're regular, but also kind of sloppy. Most are beside the road, but some are directly on it. And yes they're regular, but they're not map-quality regular, which would be very unprofessional as far as road markings go.

From that perspective, they could be almost anything. Signs. Power poles. Property access. Road quality assessment. Cute dog sightings.

Hopefully someone can provide some insights, because I'm out of ideas! Good luck with your search!

[Daistallia]

Hmm... the more I look at this, the more it looks like someone drew their own markers on an existing map. They're regular, but also kind of sloppy. Most are beside the road, but some are directly on it. And yes they're regular, but they're not map-quality regular, which would be very unprofessional as far as road markings go.

From that perspective, they could be almost anything. Signs. Power poles. Property access. Road quality assessment. Cute dog sightings.

Hopefully someone can provide some insights, because I'm out of ideas! Good luck with your search!

Hmmm... someone else asked if they were inked in as well. I'm starting to think this may be the case...