Ux117 National Parks Station Cancels W/Tagging?

I have a set of 10 National Parks Station cancel postcards. Can anyone tell me what the faint rectangle to the right of the flag might be?

The photo is deliberately darkened to make the yellowish rectangle "tagging" more visible. Except for the rectangle, the postcards have a like new creme color. I don't know if it is tagged but I don't know what else to call it.

Does anyone have any idea at what the set is valued?




Marty

Yes, Marty, that rectangle is luminescent tagging. I don't know anything about the value of the National Park Station cancels.

Thanks k,
That's what I thought it would be. I just didn't remember it being so visible when I first bought these.

Marty

On some stamps, tagging will discolor over time.

k

I find National Park pictorial postmarks interesting because I like to visit NPS sites and get my NPS Passport book canceled. I have considered starting a NP stamp cover collection. It would really highlight some of our Natural Wonders & Scenic Views.

quigngt- Could you show all 10 of your postmarks? I would really like to see them. Those sound like a nice topical collection.