xplror & Isayhello: So basically what you're saying is that: Granted, the possibility of the Imperial Valley being a northward portion of the Gulf of California, is too ancient to try to connect to the Pearl Ship legend. Ok, glad we are agreed on that

So the next explanation is to say the area of the current Salton sea was a "back-wash", so to speak, of the Colorado River. Ie.: no different than the forces that formed the current Salton Sea (engineering mistakes while canal building for ag-irrigation). The same forces were at work in 1400s/1500s, that..... back then.... could've overflowed, or temporarily diverted water from the Colorado into the the Salton Sink.
Interesting theory. My grandfather settled in Brawley in the 1920s. Before he died in the late 1970s, when I was a kid, I remember him talking about the formation of the Salton Sea, since he was nearly a pioneer of that area. Maybe not from the teens, when it was formed, but had talked firsthand with some or the even earlier pioneers. He told me that when the finally got the Colorado River back flowing the right way, and plugged the dikes or whatever, that one of the immediate concerns was "what do we do with this new giant body of water?" People naturally assumed it would just dry up, once you took away its incoming source, since..... afterall, this is the desert

But what ended up happening was, this was when ag was taking off down there. All that irrigation runoff (that didn't exist before the teens and '20s) ends up flowing into the sea, thus countering/balancing evaporation.
So perhaps back in the 1400s/1500s, a periodic such sea formed, that DID evaporate back to desert? (since there was no replenishing ag. wastewater runoff). This still seems like you're "grasping for straws". Kind of like proving UFOs or whatever, all arguments from mere extremely remote possibilities. Like, a legend is invented first, and because people so much want to believe it (afterall, who can resist a good treasure story) that they get a string of contingencies, that are wildly unlikely, and rely on a host of assumptions, to try to prop of a possibility.
Then there is the line of thought that concedes that: since the geologic proof doesn't support any flooding or ocean extensions, except in pre-historic times, therefore the pearl ship legend could STILL be true, IF you figure in that pre-historic Europeans came here! Doh

You know, like Vikings, Chinese, etc.... back 1000 to 2000 yrs. ago, way before the current era of 1492 to the present. That's like trying to debate if there is life on Saturn's moons. There is just no way to discuss that, other than speculation. Any of the non-native-indian artifacts that have been found, that purported to predate Columbus' discovery of North America, are very sparse indeed. Like.... a pre-Columbus Viking coin or artifacts in Greenland, or a mysterious chinese thingy in Oregon or Washington, etc... But they are singular items. You don't hear of entire ships and their cargo, or pearl hunting cargos and commercial trafficking, etc ... They would've been lucky just to touch our shores, on the east and the west, muchless rounding Baja CA, and finding some desert place to beach for no reason. Just doesn't make sense.
What is the evidence that chinese came to Colorado 3000 yrs. ago? Just because a legend exists in China? That's just a legend to proove a legend. Circular logic.