Hi libbyhuck, if you look through the catalog, any of the ones listed as using S30V steel are US made. Off the top of my head, that would be the Military and Para-Military, the FRN handled version of the C41 Native, the Manix, the Chinook II, the Dodo, the Yojimbo, and the titanium handled version of the ATR. The rest, including the Stretch and Impala, are all manufactured overseas, primarily in Japan.
The Stretch is one of my favorites, got one when they first came out, has been in my pocket most of the time since. Granted, I'm a bit prejudiced as I'm left handed and it's fully ambidexterous, but it also fits my hand extremely well, has a very smooth action, a large thumb hole, serrations on both the ramp and choil, and kraton inlays on both sides for a non-slip grip. No experience with the Impala, as a lefty I tend to avoid liner locks.