The “gopher” in the milk jug looks more like a thirteen lined ground squirrel, (
http://www.ianrpubs.unl.edu/pages/publicationD.jsp?publicationId=1204), rather than a pocket gopher.
I used to do something very similar with thirteen lined ground squirrels at a golf driving range in Salina, Kansas during the mid- 1950s; that was before plastic milk bottles were in use. Milk was sold in reusable glass jugs. The driving range was isolated from reinfection, as it was surrounded on all sides by a children’s playground, businesses and housing areas.
I would carry buckets of water out to the holes, pour it in, and then grab the ground squirrels around the neck (got bit a few times too). The ground squirrels were then permanently “relocated”. Oh, to be a kid again!