A live trap is not meant to be buried and if it is it will not work and the "trapped" critter will be able to get out. I have seen the killing traps trip and not hit the target, frequently.
So, do you have a live trap or a killing trap?

I assume that 'traditional wire gopher traps' mean gopher wire traps, especially since he put these into a tunnel, where they are supposed to be set.

All you can do is keep trying, lang lang. Be sure that you are setting them correctly...there's probably several tutorials on line (Youtube?) about these traps.

thanks for the replies. Yes, these are killing traps and I made sure to set them correctly. I tried again last night and put two of them back-to-back in the main tunnel, but when I checked them this morning there definitely was activity around the traps, but they were not tripped. I'm afraid the gophers have gotten wise and won't get caught.

The killing traps are very passive because they require the target animal to trip them. I know several people that think the moles, gophers, or whatever are learning how to trip them without getting caught as well as avoiding them althogether.

Success!! I caught the little bugger today! It looks like the trap just barely got him under his front legs, but it did the trick.

You might want to keep setting the traps, in case he had pals.