[cdibona]

Tunnel boring machines are extremely difficult to buy and more difficult still to run without oversight. They're just incredibly complex and hard to maintain machines. It's not impossible mind you , I mean, the cartels have all kinds of expertise available to them, but consider that the cartels have access to humans enslaved by their drug habits. Many people, fueled by cocaine, with picks and shovels can make short work of a tunnel like those described in the article.

[ChuckMcM]

You are much more practical than I am Chris. Looking at what humans, motivated by gold, did to the Sierras I'd have to concur it would be far simpler to do it your way.