I’ve actually been buying locally produced lamb exclusively for the past year, having changed my shopping habits due to the pandemic. My local whole foods often has both New Zealand and local lamb. And for a month or two they sell Icelandic lamb, which is really terrific in quality.
The other main supermarket used to mostly sell domestic lamb, and for a while had signage saying that US lamb is better to eat than NZ lamb, since ours is mostly bred for meat, and the NZ sheep are mostly bred for wool. So… Maybe it goes to my neighborhood?