I first posted this eleven years ago - here, with some minor edits it is again.
Forty-something years ago, the summer after we married, Honey and I drove the MG Midget to Big Bend National Park for our first vacation together.
We had been warned about flash floods, so when we saw thunderheads building while on a trip to Santa Elena Canyon, we made a detour to the “town” of Castolon. It seemed like a smart move at the time, but we actually ended up fording the deepest arroyo in the area, and once we stopped the car it would not start again.
The park service has a visitor center at Castolon now, but back then there was only a house for the single park ranger and a general store that catered to the Mexicans who waded across the Rio Grande to shop. We ended up spending the night with a couple UT grad students who were living there for the summer, and in the morning, a Mexican mechanic helped us get the car going again.
In a corral behind the ranger’s house there were a bunch of sad-looking donkeys. The ranger explained that they belonged to the wax smugglers who brought burro trains of chicle – the resin from the manilkara tree that is used in chewing gum – up through the park.
When a burro was injured or starving and too weak to work, the smugglers would simply cut him loose. The rangers would treat their wounds and feed them until they were well enough, then the smugglers would sneak in at night and steal them back.
Almost all US manufacturers of chewing gum have switched to artificial, petroleum-based wax for their gum, so the market for chicle has almost disappeared. There is still smuggling going on in Big Bend, but it is not nearly so innocent, and it's gotten a lot more dangerous.