A 16mm film shot in Yellowstone in 1930 that was thought to be black-and-white is actually color/National Archives

A vintage movie, typical of a "home movie," shot in Yellowstone National Park decades ago is being restored by the National Archives, casting a unique light on park visitors of an earlier day. What's particularly interesting is the grainy 16mm film, thought to be black-and-white, actually was shot in color, making it one of the first color films to be shot in the park.

The movies show visitors milling about the park much as they do today, enjoying the thermal areas, hiking lakeside trails, and celebrating the arrival of a "Senator Rule" to the park, an event marked with a cake bearing "Welcome Senator Rule" spelled out in frosting.

The movies had been buried in a storeroom at the National Park Service's Harpers Ferry Center in West Virginia.

"We had a very large storeroom of film, some of which was starting to show signs of decay. The Center'™s been open since the '70s, but some of this film goes back to the '20s. We'™re not sure where it came from," Janice Wheeler, in the Center's technical services division, said. 'œThis is part of collection....it was stuff that they had researched to create another film, another product. It was on our shelves. Here it is, 23 years later. We didn'™t know what it was, so we sent the entire collection to the National Archives because they were in a better position to ensure the longevity of the film itself.'

All told, the Center's historic films collection contains about 100 16mm films that were shot years ago for a Park Service project, "National Parks, an American Legacy." The films were sent in 2012 to the National Archives, where the staff earlier this year received a grant to restore and document the films. Among the first restored have been snippets of what initially appeared to be black-and-white movies, but which upon restoration turned out to be color movies.

"So, what would you do if you found what just may be the first color moving image footage of Yellowstone, but it was disguised as black and white images? Well, the staff in the NARA Motion Picture units got pretty darn excited because we'™d just stumbled across some very rare film stock and truly unique footage!," Criss Kovac, supervisor of the National Archives Motion Picture Preservation Lab, wrote in a blog post. "As we were going through our accessioning inspection process, we came across a reel that appeared to be black and white, but the words on the edge said, 'KODACOLOR.' Other edge markings told us that the film was shot in 1930. With that bit of information, we realized that this reel could be among the earliest color films of Yellowstone National Park."

Deciphering exactly when the movies were made, and by whom, remains a larger mystery. They possibly could have been shot by Jack E. Haynes, the park's official photographer at the time, though that hasn't been determined. "Senator Rule" apparently was Sen. Arthur L. Rule, a state senator from Iowa.

Also solved was the mystery of the why the color film initially appeared to be black-and-white.

"An early reversal color home movie format produced by Kodak, Kodacolor, only existed for a handful of years, beginning in 1928, until it was replaced by the much more successful Kodachrome in 1935," wrote Kovac. "Kodacolor appears to the human eye as black and white images, but the base side of the film is embossed with hundreds of tiny lenses (called lenticules) that look like minuscule ridges on the surface of the film base. The lenticules captured the color information from the scene while it was filmed through a color filter with red, green, and blue-violet stripes. In order to see the color the film then had to be projected back through a similar color filter."