Jog & Dahut: I believe this idea that indians had these Chinese coins "even before the white man came" is incorrect. It's merely an assertion, just because the coins were found (archaeologically for instance) in indian village sites. It simply doesn't follow logically that since 1) the coin dates to the 1600s, and 2) it was found in an indian village site, that 3) therefore the Chinese must've been here before any European got here!
Here's why the logic doesn't work that way, in a way that only an md'r would understand: For starters, Chinese coins of this period are found, as is pointed out by others on this thread, even in simple western era sites (that would've had Chinese immigrants in the 1800s for fishing, gold rush, RR building, or whatever), right? I mean, for example: I've found those Chinese coins by the dozens. And yes, some of them date to the 1600s I suppose. And they were found in places where we'd be finding seateds or other such mid 1800s sites. They were simply a coin that was lost even as late as the mid to late 1800s, and yes, even though they can date to the 1600s.
Having hunted a lot of contact period indian sites (which were both pre-historic and contact period), it is not unusual to find whatever you might expect to find in any other site of the time-period. Although an archie may be digging a pre-contact site, there's nothing to have stopped something to be lost there during the contact times. Villages continued to exist often time, both before, and during the contact period, unless conclusively known otherwise, strata-wise, or whatever. Who's to say the coin wasn't lost there after European contact? So it would not be unusual to find a chinese coin (or reale, or early seated, or whatever) in these sites. But the minute you get some zealous newbie archie to happen to find a 1600's chinese coin there, having not been exposed to the proliferation of, yes even wickedly old ones circulating for insanely long times, they muse "gee, I guess the Chinese were here way long ago!"
Not saying Chinese or any other people groups didn't get here earlier than Columbus or whatever, just saying the random find of a 1600s chinese coin doesn't prove anything. Also be aware that although the west coast didn't get the first permanent habitation till 1769 (San Diego), there had been a few centuries of occasional ships stopping to take on water, explore, map, etc... And they did trade with the indians. For example, there is an indian midden site by Santa Barbara, near the Channel Islands, where coins that way predated the Santa Barbara mission have been found (coins and buttons back to the 1500s I believe). This was because ships stopped to trade or take on water whilst coming back from the Manilla trade. So metal items did get into the trading system. And think of it, they weren't necessarily *only* Spanish coins. Who's to say they didn't have other coins of other ports (including Chinese) they'd stopped at?
If a coin found somewhere is proof that those people groups were here at that time, the I guess the Romans beat them all, 'cuz a friend of mine found a first-century Roman coin in a demolition site in Monterey, CA
Now how do you explain that?? haha
Obviously someone brought it back as a souvineer and lost it here, right? So old coins can enter the oddest sites.