Swimming in Yellowstone rivers, aside from in a small stretch of the Firehole River, along the Gardner River outside of Mammoth Hot Springs, and in the Bechler region, is prohibited. Yet rangers don't seem to be enforcing that rule very stringently.

During a trip to the park last week I saw quite a few swimmers, waders and bathers in the Firehole River near Biscuit Basin and near Fountain Flat Drive. Yet the only stretch of the Firehole legally open to swimming is along the Firehole Canyon Drive just north of Madison Junction.

Is this a big deal? Probably not at this point, although those taking a dip near Biscuit Basin could possibly get burned by some of the thermal waters flowing into the river. Too, as the park newspaper points out, "Thermal water can also harbor organisms that cause a fatal meningitis infection or Legionnaires' disease."

Beyond the health concerns, if Yellowstone's rangers continue to turn their heads to this activity, how long before dozens of folks are taking a dip and floating the stretch of the Firehole between Biscuit Basin and Fountain Flats?

How long before this beautiful stretch of river begins to look like the Merced River flowing through Yosemite Valley with its flotillas of rafters, tubers, and swimmers?