The past and present collided when the National Parks Service recreated a number of 1930's panoramic photos of fire lookouts, this time with modern photographic technology. The results are viewable in an interactive format that's helping the NPS study the changing landscape of U.S. National Parks.

From the National Parks Service website: "In the early 1930s, the US Forest Service embarked on a panoramic photography project that utilized lookouts and lookout points in order to create maps for fire lookouts." In 1934, the National Park Service set about their own documentation project across the country with the help of an Osborne photo-recording transit and a photographer named Lester M. Moe. The panoramic photos that resulted helped decrease response times to wildlife fires. 

What's left of Moe's 1930's photos have been digitized with the help of Gigapan, and a 2007 project aimed to duplicate the photos in present day from the same angles as the originals. Park surveryors used infrared film for the modern comparison shots to reduce the hazy effect of pollution and keep land formations in the distance visible. 

The July 30 1935 photo on the left shows Glacier National Park's Huckleberry Lookout in contrast to the infrared photo from 2009 on the right. Click the image above to view photos using the interactive tool. Photographs by Lester Moe (left) and Ian Grob (right). 

The comparison photos provide useful information about how vegetation and landforms have changed over the years. There's also an element of participation - viewers are invited to submit any differences they see between the past and present photo to help the NPS study the changes in the landscapes. 

Take a look at panoramic photos from Glacier and Yellowstone National Parks and see for yourself how these landscapes have changed over time.