Does time change all? Sometimes, to some degree. But a new book on Yellowstone National Park places photographs side by side to show that sometimes that change is not as much as you might imagine over a period of decades.

Compiled by Paul Horsted and Bob Berry, Yellowstone Yesterday & Today is one of those "then-and-now" projects that accurately measures how time, and humans, have changed landscapes down through the years. In some cases, that change in Yellowstone can be quite substantial.

Take Orange Spring Mound at Mammoth. When T.W. Ingersoll photographed it back in 1888, the "mound" was known as "Orange Geyser Cone, Extinct," as the label on his stereoview read. But when Mr. Horsted traveled to the scene on October 9, 2011, to photograph the setting, his shot was of "(O)ne of the fastest-growing formations in the Mammoth area..."

"The water that flows out across the surface at several locations is constantly depositing minerals, building the mound many feet taller than it was 123 years ago," the photographer noted in the short narrative that accompanies the side-by-side photos. (Adding to the unique approach Mr. Horsted took to arranging the photographs in his book, these two shots -- the one from 1888 and his own -- are framed by the stereoview border that wrapped Mr. Ingersoll's original shot.)

This new book compares the past and the present -- side by side -- of Yellowstone National Park

Another sign of change can be found in the photographs of Mammoth Hot Springs and its hotel, taken from a hillside overlooking the setting with the travertine terraces in the background.

In the first shot, taken in 1884 by Carleton E. Watkins, the hotel in the foreground is the old National Hotel that was built in 1883. That hotel was long gone when Mr. Horsted arrived on June 6, 2012, to document the setting. In its place stood (and still stands) the Mammoth Hot Springs Hotel built between 1938 and 1938, and the old stagecoach route from the 1880s is no longer the main route into Mammoth, but rather a graveled route open only in summer for one-way traffic from Gardiner, Montana, to Mammoth.

Some of the changes depicted by the photos reflect natural events. For instance, Bath Lake, which was a favorite swimming hole in 1883 when F. Jay Haynes photographed it, but "dried up 1926, then filled again following a 1959 earthquake. It has now been dry since 1984," Mr. Horsted notes.

As fun as putting this collection together must have been, it also was no easy task. Mr. Horsted turned to Mr. Berry to search through his personal collection of more than 3,000 historic photographs of Yellowstone as he pieced together locations that would go into the book. He also went through "several hundred more in the Library of Congress, Yale's Beinecke Library, and other sources in order to gather the 103 sites contained in this book," points out Lee H. Whittlesey, Yellowstone's in-house historian.

Of course, selecting a location in a historic photo, and then identifying exactly where in the park the photo was taken, and from what location in relation to the subject matter, also was a bit tricky. A lot of gazing out of car windows, and walking around the landscape while looking at the subject matter, was involved.

And, of course, over the years some landscape features had been altered. Trees were either gone, dead, or newly grown up, rocks might have taken on different hues, vegetation might obscure views that were open 100 years ago. And then there was the issue of modern park regulations.

"One obstacle Bob and I encountered was the restricted access to places where visitors (and photographers) once roamed freely -- across thermal areas, over the flowing formations at Mammoth Hot Springs, and to the bottom of the Grand Canyon of the Yellowstone," points out Mr. Horsted.

Many then-and-now photos in the book are laid out as old stereoviews.

"Those areas are now closed (or movement is restricted to boardwalks and overlooks) by the National Park Service for logical reasons of conservation and visitor safety. This meant it was impossible to rephotograph an extreme close-up view of Old Faithful, for example, but we had available a number of more distant views of the eruption of this famous geyser. I was fortunate to have Bob's collection of more than 3,000 historic photos -- plus a few dozen more from other sources -- to give us the best possible combination of interesting and representative images to include in this book."

To help negotiate the photographs in the book, the authors added some helpful notations. Naturally, they clearly noted the year and location of the historic photograph, sometimes resorting to "circa" if there was no clear date. If known, they also noted who took the historic photo.

To these data were added the date Mr. Horsted took his photograph along with the GPS coordinates of the site, a short narrative explaining the setting, and occasionally even a footnote of personal notes Mr. Horsted contributed, such as his comment attached to then-and-now photographs of "Great Falls and Grand Canyon of the Yellowstone" that "(S)unrise is a beautiful time to watch the Lower Falls. As the sun breaks over the canyon rim behind this overlook, it often sends a shaft of light across the falling water."

For anyone who has an abiding interest in Yellowstone, this is an intriguing and even fun book to page through and take to the park to compare to the settings you see. And with the GPS coordinates, you can even try your hand at then-and-now photography.