Living things change constantly, as do communities of living things. In a forest, where individual trees can live for centuries and new plants replace old plants, it is not easy to visualize the changes that occur over time. Luckily, we have some records and photos that illustrate how forests change. This poster shows how one stand of ponderosa pine (Pinus ponderosa), located in the Lick Creek drainage of the Bitterroot National Forest, Montana, changed throughout the 1900s. The initial photo was taken in 1909 to document a timber sale, the first large harvest of ponderosa pine from the northern Rocky Mountains. Sadly, there is no photo of the stand before that first harvest, which removed about half of the large pines on the site. Afterwards, however, photos were taken periodically from exactly the same spot. Now, nearly a century later, the photo series illustrates both immediate and long-term changes on the site. Especially noticeable are increases in tree density and a shift from ponderosa pine to Douglas-fir (Pseudotsuga menziesii) dominance. This kind of change took place in both logged and unlogged ponderosa pine forests of the northern Rockies during the 1900s. Note: This poster is the original poster from E224. E224 has the updated poster of this in the back pocket of the publication.