When America's National Park Service (NPS) was formed in 1916 by President Woodrow Wilson, it had just 35 parks and monuments under its protection. That number rose significantly in the 1930s, when a series of orders expanded their reach, and more national parks were developed. Today, the NPS manages more than 400 parks and monuments.

During the period of expansion in the 1930s, the NPS created so-called "master plans" that showed the vision for each park. They included maps, drawings and text describing the proposed developments, according to the National Archives.

Roads, hiking trails, management buildings, visitor stations and parking lots were all sketched out in these thoughtful, hand-colored plans that hold up today as visionary works of art. The cover of the master plan for Yellowstone National Park is above, for example, and a modern scene is below. Scroll down to see more plans from this era, and to compare with the parks of today.

Castle Geyser at Yellowstone National Park.
Castle Geyser at Yellowstone National Park. (Photo: Brocken Inaglory/Wikimedia Commons)

There are more geysers at Yellowstone National Park than anywhere else on Earth, according to the NPS. In fact, the park is home to about half the geysers in the world, so it's no wonder the NPS chose to feature them on the cover of the master plan.

Great Smoky Mountains, 1939
Great Smoky Mountains, 1939 (Photo: National Archives and Records Administration)

The cover of the master plan for Great Smoky Mountains National Park in North Carolina and Tennessee showcases the mountains in the background with meadows and trees in the foreground. The picture below — of the Cades Cove section of the park — is a modern representation of the same scene.

Cades Cove in the Tennessee section of Great Smoky Mountains National Park.
Cades Cove in the Tennessee section of Great Smoky Mountains National Park. (Photo: Dave Allen Photography/Shutterstock)

The NPS says Great Smoky Mountains National Park is the most visited national park in the United States, and Cades Cove is the most popular destination within the park for its scenic views of the ancient mountains and the diversity in plant and animal life.

Master Plan for Rocky Mountain National Park, circa 1938
Master Plan for Rocky Mountain National Park, circa 1938 (Photo: National Archives and Records Administration)

The master plan creators were extremely thorough and accounted for everything at each site.

According to the National Archives, the plans also included "items relating to the physical landscape. Plan sets include maps showing land cover and vegetation, reforestation efforts, and fire control plans. Many of the sets also include topographic or landform maps."

A bighorn sheep in Rocky Mountain National Park.
A bighorn sheep in Rocky Mountain National Park. (Photo: Endless Traveller/Shutterstock)

Bighorn sheep are the symbol of Rocky Mountain National Park, the NPS says, which is why they were featured so prominently on the cover of the 1938 master plan. As you can see in the photo above, the largest wild sheep in North America still roam the gorgeous landscapes of the Rocky Mountains today.

Crater Lake National Park, 1933
Crater Lake National Park, 1933 (Photo: National Archives and Records Administration)

Crater Lake in Oregon formed 7,700 years ago when a violent volcanic eruption triggered the collapse of a tall mountain peak, according to the NPS. Fed by rain and snow in the Cascade Mountain Range, it’s the deepest lake in the United States and one of the most pristine on the planet, the NPS says.

Crater Lake in Oregon
Oregon's Crater Lake is six miles wide and the deepest lake in the United States. (Photo: Charles Dawley/flickr)

Today, Crater Lake National Park looks pretty much exactly as it did on the cover of that 1933 master plan. And yes, the water really is that blue.

Fort Pulaski National Monument, 1937
Fort Pulaski National Monument, 1937 (Photo: National Archives and Records Administration)

Fort Pulaski National Monument in Georgia played an important role in the Civil War. According to the NPS, these kinds of "masonry fortifications" had been a prime source of defense prior to that time. As military technology advanced, however, the Union army was able to use rifled cannons and compel the Confederate troops inside Fort Pulaski to surrender.

Fort Pulaski National Monument
Fort Pulaski National Monument in Georgia in 2002. (Photo: Edibobb/Wikimedia Commons)

Today, the NPS calls Fort Pulaski a "large-scale outdoor exhibit. The main structure, together with outlying works including demilune, drawbridges, ditches, and dikes, is a fine example of historic military architecture."

Grand Canyon National Park, 1938
Grand Canyon National Park, 1938 (Photo: National Archives and Records Administration)

The Grand Canyon first received federal protection in 1893 as a forest reserve and then a national monument. But it didn't become a national park until 1919, according to the NPS. The park has been home to humans for more than 10,000 years, according to archaeological evidence.

Grand Canyon National Park's Cedar Ridge.
Grand Canyon National Park's Cedar Ridge. (Photo: Grand Canyon National Park /Wikimedia Commons)

Today, Grand Canyon National Park encompasses 1.2 million acres in Arizona. It is one of the most popular parks in the U.S. with nearly 5 million visitors a year, and one of the most studied geologic landscapes in the world, the NPS says.

And several modern tribes, such as the Havasupai and the Navajo, still call the Grand Canyon home.

Mount Rainier National Park, 1933
Mount Rainier National Park, 1933 (Photo: National Archives and Records Administration)

Like the Grand Canyon, the area around Mount Rainier in Washington has been home to Native Americans for thousands of years — 9,000, to be exact, according to archaeological evidence.

In 1899, Mount Rainier became the nation’s fifth national park, and attendance there ballooned so quickly that park administrators and nearby developers struggled to keep up. A lack of roads led to traffic jams, and there was a shortage of lodging and other services.

Tatoosh mountain range in Mount Rainier National Park.
Tatoosh mountain range in Mount Rainier National Park. (Photo: Michelle Mealing/Shutterstock)

At 14,410 feet above sea level, Mount Rainier was and continues to be an icon in the Washington landscape. It's an active volcano and, according to the NPS, it's the most glaciated peak in the contiguous U.S., spawning six major rivers.

Mount Rainier is an outdoor sports enthusiast's paradise, with 260 miles of hiking trails and ample opportunities for climbing, fishing, boating and camping.

Vicksburg National Military Park, 1936
Vicksburg National Military Park, 1936 (Photo: National Archives and Records Administration)

The tone of this master plan for Vicksburg National Military Park along the mighty Mississippi River is strikingly different from the previous master plan covers. Stark black, white and gray shades replace the pastel coloring seen in the plans above. No sweeping vistas here. Instead, a lone cannon on a hill and a bare tree express the solemnity of the site.

Like the Fort Pulaski National Monument, Vicksburg played a pivotal role in the Civil War because the Mississippi River was the "single most important economic feature of the continent" at that time. As the NPS reports:

President Abraham Lincoln told his civilian and military leaders, "See what a lot of land these fellows hold, of which Vicksburg is the key! The war can never be brought to a close until that key is in our pocket...We can take all the northern ports of the Confederacy, and they can defy us from Vicksburg." Lincoln assured his listeners that "I am acquainted with that region and know what I am talking about, and as valuable as New Orleans will be to us, Vicksburg will be more so." ...

In the spring of 1863, Major General Ulysses S. Grant launched his Union Army of the Tennessee on a campaign to pocket Vicksburg and provide Mr. Lincoln with the key to victory.
Vicksburg National Military Park in Mississippi.
Vicksburg National Military Park in Mississippi. (Photo: rusty426/Shutterstock)

Today, the NPS says Vicksburg National Military Park offers "several ways to experience the vast array of historical, cultural and natural resources throughout its park grounds." Take a tour with a guide, listen to an audio tour while you drive around in your car, or tour the 1,400 monuments and memorials located at Vicksburg.

Death Valley National Park, 1935
Death Valley National Park, 1935 (Photo: National Archives and Records Administration)

Many things have left Death Valley National Park over the years, like the gold prospectors with their donkeys and the towns and mining camps that sprung up as a result of their presence. This land of extreme heat and extreme drought is another region where native people have lived since at least the end of the last ice age.

Zabriskie Point in Death Valley National Park, California.
Zabriskie Point in Death Valley National Park, California. (Photo: MNStudio/Shutterstock)

But nowadays, Death Valley National Park is known for its rare wildflower super blooms that pop up after rainstorms, its ultramarathons, its lush oases and its diversity of animal wildlife.