Another thing I've learned over the years is that when confronted with a series or multiple mounds, one has a tendency to locate main tunnels and set traps in the fresh/new mounds. I'll usually put out 2 trap sets in this situation. One trap set will be at or close to the oldest/first mound thrown. The second trap set will be located anywhere in between the oldest and newest mound. The majority of my gopher catches will be at the first/older mound trap sets. In this scenario, I'll also only use PB at the second trap set (towards the fresh/newest mound) and none on the first trap set (first/older mound).
Another tip pertains to trap covers. I'm in sandy soils and I make it a point to scrape the underside of my trap covers near the mound after I check and pull my traps. Why? Condensation! That may be good or bad I'm guessing depending on the season. Just a SWAG but there's gotta be some pocket gopher "pheromones" mixed in that condensation. Could be a reason for gophers (sub-dominant or juvenile) plugging in front of my traps or completely covering up my trap set. During gopher breeding seasons (we have two!), this may be a good thing as females indicate they are ready and males compete for them. Again, just a guess on my part but it only takes a few seconds to scrape my trap covers on that 500 grit gopher mound sand next to me.