The biologists use the data from the receivers to track elk herd movements into and out of the park. The Park Service biologists say they coordinate their elk management efforts with their counterparts in the South Dakota Game, Fish and Parks Department.

Dan Roddy says, "We have a general idea of how many elk we can support in the Park. So with that in mind we're trying to lower out elk population down to the number that was established in our elk plan, which is somewhere in the neighborhood of 230 to 475."

To capture the elk, the Park rangers use a snare net launched from a helicopter operated by a company which regularly does contract flying for the Park Service.

Al Van Zee