I have been told this type of work is typically Hopi, but of course styles are often imitated.
I found this site which, unfortunately, only lists it as "Unidentified---please help", so apparently I'm not the only one wondering about what this is.
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I include that because theirs looks like a better picture and also shows how it looks upside-down from how I saw it at first, which might affect interpretation---is it CH or HJ?