The "River Rats" were a wartime fraternal organization of US Air Force pilots who flew over North Vietnam during the Vietnam War. The group was formed in 1967 to improve tactics and coordination. The name "River Rats" comes from a river that runs through North Vietnam. The Red River (seen in the patch) runs through Hanoi (the yellow star in the design). The patch is a shield with a black background color and a yellow border, a depiction of the Red River and yellow star (for Hanoi) in the center, and the words "River Rats" embroidered in red, in all capital letters, usually enhanced graphically with a white dashed-line outline around each letter. Nice example, has been sewn on (stitching holes around the outer edge). 75

Of Note from the Vendor: these River Rats patches are reproduced, but this is a correct original patch, it was removed from a Wrangler Jeans jacket from the late 1960’s that I found at a vintage clothing store. All the patches on the jacket were original 1960’s U.S. patches. There are a large number of variations of this novelty patch, which was made in both Thailand (where most of the Air Force flyers were based) and in the US. This particular variation is vouched for in post # 13 on the US Miltaria Forum thread on River Rats patches found here:

https://www.usmilitariaforum.com/forums/index.php?/topic/180721-post-your-river-rats-novelity-patches/