Hey guys. I am completely unfamiliar with western saddles but there's a Sharon Saare saddle on Craigslist I'm interested in that has a tree size of BHG. I can't figure out what this means, though the seller says it should work for a TB. Any ideas? I saw somewhere that the tree sizes start at A and go through G, but I can't find reference to a combination of letters like this.

I'm trying to find a western saddle to fit my new TB mare, so if any of you have any suggestions on what I should be looking for (used), please let me know. Here's a picture of her back. Thank you!
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