It's a keeper either way as it is a low mintage NIFC coin, as is the 2004 in the other thread. My first thought was die crack. But IDK what it is.
i just looked again with my 45X, i just dont see any protruding, more inverted. (coin lingo needs work) a keeper either way as pointed out.
Looks like a possible lamination error, but I know little to nothing about Sacajawea coins, so take my idea with less than a gain of salt.
Lamination, die crack or a defective planchet, I can't tell but it's a keeper. Nice find! Protect it.
