Long overdue update on this, but I found my traps! I found them in late 2020, behind my shed, about 30' away from where I'd used them. During the same period of time I put up some trail cameras and got a lot of good video of our growing coyote population:
https://www.youtube.com/watch?v=LCG4YcW ... 9&index=46
Furthermore, more recently I'd caught a few more gophers in my tomato patch and buried them right back in the tunnels where I'd caught them, under the theory that the macabre scene would discourage other gophers from moving right in.
Someone smelled the carcasses and dug them right back up:
They also chewed off all 8 emitters and chewed holes in the main supply hose:

I think I can submit this to the DA and charge the coyotes.