There's a chance I could make a mistake on a detail here and there; I rarely, if ever, remember these dreams with perfect clarity, even right after I wake up. However this is, the best I can recall, what the dream was:
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One or more companions and I were out in nature, kind of in a desert-looking area, at the Mexican-American border, on the American side. We were accompanied by one or more guides. (This was not a border-crossing station, but just some place out in nature, more or less.)
This was right by the Rio Grande, although since it's now 2021, the river may or may not have slightly moved out of perfect alignment with the border over the course of time. In fact, the guide(s) were describing to us how the geography around the border in that particular area or whatever had actually changed quite drastically since the modern border in that area was established, back in the 1800s or whatever.
There were images - either ones that I saw physically, or ones that I imaged - moving images that were like a time lapse video of the appearance of the earth changing there, from since the modern border through there was established to the present day. It was quite drastic. Very visible differences in the presence of a body(ies) of water / river(s), hill(s) and cliff(s), topography, everything.
One thing though that was different now from what it was at the beginning - when the current border through there was established way back in history - was that, on the Mexican side (opposite us), the elevation had come to be much higher, and there were one or more cliffs from the bases of hills/mountains all the way up to the top, with that dry, desert-looking cliff(s) facing us. Also, the area was dryer, less green, more desert-looking, and without a river flowing through it - whereas there had been a gushing river in the past. These days, at least, there was some water at the top of that hill(s)/mountain(s)/cliff(s), but it was less than the river, and it was hidden or almost hidden from our point of view.
The guide(s) said that the cliff(s) on the Mexican side were like a thousand miles away from us. But to me, they looked to be just on the other side of the border, not far from us at all. Even though the guide(s) were saying the cliff(s) were 1,000 miles away, I remained doubtful. Maybe the mountain(s)/hill(s) were just so big, that at 1,000 miles away, they could produce an illusion to look like a normal-sized hill(s) or whatever within just a few miles . . . but is that really possible? Could it really be an illusion? Surely...surely, as I continued to look at that dry, deserty cliff(s) in Mexico, with the certain amount of water on top...surely they can't really be an illusion 1,000 miles away, could they? I mean, they almost have to be very close to where we are, regardless of what the guide(s) are saying.
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I have felt good about this dream. Without specifying context behind the dream, there's something in particular that I feel like it's tied to.