Officials with the U.S. Forest Service say the battle against pine beetles in South Dakota will likely continue for some time.
Black Hills National Forest Deputy Supervisor Dennis Jaeger says trends show that beetle infestations continue to rise after a downward trend from 2006 to 2009.
The bugs have killed millions of trees in the Black Hills in the last year.
Jaeger says the effort to control the beetles includes include thinning, regular timber sales, and prescribed fire.
Jaeger says that it takes a "unified approach and a strategy" to combat the bugs.