I’d be extremely suspicious of this one. Looks like block (plastic) turquoise to me. I wasn’t familiar with Dean Brown, but it looks like he was a real Navajo artist, a nephew of Kirk Smith who trained with Kirk, and worked in a similar style. These are some examples I found on the internet of his work:
As expected they resemble Kirk Smith’s work more than the bracelet you posted. They also exhibit much higher quality silver work. Compare the bezels, for example.
And here is his hallmark, which is not an exact match for yours:
Agree with @OrbitOrange it’s block turquoise and not by Dean Brown. I found a bracelet sold as by Davin Benally, Navajo, with a similar DB who does work in block turquoise. I hope you paid something fair. Here’s a cluster bracelet, made in multiples, that retails for $132:
I don’t think we’ve established whether it is an import or not. Yes, there are Native American artists that use block and other lower quality materials like composite turquoise. Davin Benally is apparently one of them, and it could be him. But these generic two initial stamps are notoriously difficult to identify, and often associated with imports. The stamp on the OP’s bracelet is also not an exact match for that on the Etsy bracelet that @chicfarmer poster. The letters on that one are thinner, and taller. Could still be him–maybe he used different stamps at different points. Or not. These cluster styles are also one of the most common styles made overseas. With the combination of block turquoise, generic two letter initials, and cluster style, I remain suspicious.
I’m on the same thought track as @OrbitOrange. Found this with the Davin Benally Hallmark, but attributed to Dean Brown (wrongly I think). They are actually staying that it’s howlite.