Petrified Forest National Park, Arizona
Nestled between Navajo and Holbrook in the northeastern expanse of Arizona, along the well-traveled Interstate 40 and the historic Route 66, lies the Petrified Forest National Park. This park is not merely a scenic stop along a journey; it is a captivating realm of geological wonders, a testament to time, and a repository of ancient stories etched in stone. Within its boundaries, one discovers a landscape unlike any other, a surprising panorama of vibrant colors, intricate formations, and profound scientific significance. The park boasts one of the world’s most extensive and visually stunning concentrations of petrified wood, the multi-hued badlands of the Chinle Formation, famously known as the Painted Desert, historic structures whispering tales of the past, significant archaeological sites, and fascinating displays of 225 million-year-old fossils.
The Petrified Forest National Park is divided into two primary sections, connected by a corridor stretching from north to south. The northern section showcases the mesmerizing Painted Desert, a symphony of colors painted across the landscape. The southern region, in contrast, features a diverse terrain dotted with several concentrated deposits of petrified wood. Furthermore, the southern area contains several sites adorned with American Indian petroglyphs, offering a glimpse into the lives and beliefs of the ancient inhabitants of this land.
The park’s natural environment is far more intricate than a casual observer might initially perceive. Situated near the southern edge of the vast Colorado Plateau, the Petrified Forest National Park forms part of a remarkable geological region, sharing kinship with other renowned natural landmarks such as the Grand Canyon in Arizona and Zion, Bryce Canyon, and Arches National Parks in Utah. Each of these parks showcases a distinct chapter of the Earth’s geological narrative.
Over two hundred million years ago, during the Late Triassic period, the area now encompassed by the Petrified Forest National Park was a vastly different place. Towering trees and lush vegetation thrived in a tropical wetland environment, characterized by abundant streams and rivers. During periods of heavy rainfall, these waterways would overflow, sweeping fallen trees into the sandy floodplains. Later, volcanic activity reshaped the landscape, burying the ancient forest under layers of volcanic ash, mud, and waterborne sediment. The trees underwent a remarkable transformation, transitioning into stone through a process called permineralization. This process involved the gradual replacement of organic materials with minerals, primarily quartz, effectively creating a stone "cast" of the original organism. Millions of years later, erosion gradually unveiled these petrified logs, revealing the stunning spectacle we see today.
The vibrant, banded coloration that characterizes the Chinle Formation badlands of the Painted Desert is largely attributed to soil formation processes that occurred during the Late Triassic period. The soil composition suggests a climate with dramatically distinct wet and dry seasons, a climate perhaps similar to the modern monsoon patterns observed in the Indian Ocean region.
The colorful mudstones and clays that make up the Painted Desert badlands are primarily composed of bentonite, a product of altered volcanic ash. The clay minerals within bentonite have a unique ability to absorb water, and their subsequent expansion and contraction properties contribute to rapid erosion. This erosion process inhibits vegetation growth on the slopes of the hills, maintaining the barren, yet visually striking landscape.
Other prominent features shaped by erosion within the Petrified Forest National Park include numerous mesas and buttes. These formations are characterized by flat tops consisting of more erosion-resistant sandstone overlying softer clays. Mesas tend to be broad and relatively low in height, while buttes are typically taller and narrower.
The Petrified Forest National Park is also rich in human history, spanning back over 13,000 years. Archaeological evidence suggests the presence of human activity dating back to the Paleo-Indian period. To date, more than 600 archaeological sites have been identified within the park’s boundaries. These sites contain artifacts such as Folsom-type spear points, representing some of the earliest evidence of human presence in the region. Furthermore, numerous other artifacts, petroglyphs, and the remains of ancient pueblos, built by later inhabitants, have been discovered, providing invaluable insights into the cultural heritage of the area.
From the 16th through the 18th centuries, Spanish explorers seeking routes between Spanish colonies along the Rio Grande and those on the Pacific coast often passed near or through the area known as El Desierto Pintado, or the Painted Desert. However, the oldest surviving Spanish inscriptions within the park date only to the late 19th century, left by descendants of the region’s early Spanish colonists.
The Petrified Forest National Park initially gained recognition as a National Monument on December 8, 1906, primarily to protect the area’s unique petrified wood deposits. The Painted Desert was later incorporated, and on December 9, 1962, the entire monument was elevated to National Park status. Today, the park encompasses 93,532.57 acres, a testament to its significance and the need for its preservation.
The Painted Desert Inn, a landmark within the park, was originally constructed in 1924 by Herbert Lore on a prominent perch overlooking the Painted Desert. Nicknamed the "Stone Tree House" due to the extensive use of petrified wood in its construction, the inn served as both a lodging establishment and a tourist attraction.
This isolated oasis was acquired by the Petrified Forest National Monument in 1936, leading to renovations and upgrades. It subsequently became the park’s headquarters and served countless travelers along Route 66. The inn closed its doors in 1963 and remained vacant, deteriorating for many years. Today, it has been fully restored and serves as a museum, offering visitors a glimpse into the past.
The petrified wood found in the Petrified Forest National Park holds the distinction of being the "State Fossil" of Arizona. These permineralized wood specimens originate from a family of trees that are now extinct in the Northern Hemisphere, surviving only in isolated regions of the Southern Hemisphere.
During the Late Triassic period, this region experienced a seasonally wet and dry climate. During periods of flooding, trees were transported from their original growing locations and accumulated in sandy river channels, subsequently being buried under layers of gravelly sand rich in volcanic ash originating from volcanoes located further to the west. The silica within the volcanic ash played a crucial role in the permineralization process, replacing the wood with silica and imbuing it with vibrant colors derived from oxides of iron and manganese.
Key landmarks within the park include the Agate House Pueblo, constructed entirely from petrified wood; the Agate Bridge, a remarkable petrified log spanning a wash; the Painted Desert Inn, a designated National Historic Place; a preserved segment of the historic Route 66; and the Puerco Pueblo, along with numerous scenic formations and hiking trails.
Agate Bridge
Approximately 225 million years ago, numerous tall trees were swept into the floodplain, where they were buried under layers of silt, mud, and volcanic ash. The sediment deprived the logs of oxygen, slowing down their decomposition. Silica-rich groundwater seeped through the logs, gradually replacing the original wood tissues with silica deposits.
Over time, the silica crystallized into quartz, resulting in the preservation of the logs as petrified wood. Centuries of scouring floodwaters eventually washed out the arroyo beneath this 110-foot-long petrified log, creating a natural bridge. The petrified log, being harder than the surrounding sandstone, resisted erosion and remained suspended as the softer rock beneath it was carried away.
Recognizing the significance of this natural wonder, early conservationists established the Petrified Forest National Monument in 1906 to preserve it. To provide additional support, masonry pillars were erected beneath the log in 1911. In 1917, these pillars were replaced with a concrete span, which remains in place today.
The current philosophy of the National Park Service emphasizes allowing natural processes to shape the landscape. If discovered today, Agate Bridge would likely be left in its natural state.
Agate House
The ancestral Pueblo people utilized petrified wood for various purposes, including crafting projectile points, knives, and scrapers. Agate House exemplifies another innovative application of petrified wood: as a building material for masonry structures. Approximately 900 years ago, the ancestral Pueblo inhabitants constructed this small, eight-room pueblo near agricultural fields and petrified wood deposits. Its size and the resources required for its construction and maintenance suggest that it was not a temporary residence but rather a year-round dwelling for a family unit. Some researchers propose that it served solely ceremonial purposes. The structure was likely occupied for less than a generation or thirty years.
Archaeological evidence suggests that Agate House was constructed and occupied between 900 and 1200 AD. The ceramic assemblage discovered during excavation included coiled utility ware and various black-on-white painted ceramics, along with a few examples of black-on-red pottery. While most pottery appears to be associated with ancestral Puebloan people, some may have southern origins, possibly associated with the Mogollon culture.
According to a 1933-34 site excavation report, Agate House was constructed using medium to large pieces of petrified wood, presumably carried to the top of the knoll. The walls were originally constructed of petrified wood held together by mud mortar and chinked with smaller pieces of petrified wood. The pueblo is thought to have been occupied for a brief time, based on the limited cultural debris found in the area. The rooms were reconstructed following archaeological excavation in 1934.
Agate House is located on a small hill within the Rainbow Forest. While some questions remain regarding the accuracy of its reconstruction, it provides a valuable glimpse into the daily lives of the ancestral Puebloans. Agate House was listed on the National Register of Historic Places in 1975.
A two-mile round-trip trail leads from the Rainbow Forest Museum parking area to Agate House. The first half-mile of the trail is paved and accessible to strollers and various mobility devices. The remaining portion of the trail is narrow and uneven, potentially unsuitable for some wheelchairs and other equipment. Upon reaching Agate House, visitors are asked to leave all archaeological artifacts in place for others to appreciate and to refrain from sitting, standing, or leaning on the fragile walls.
Painted Desert Inn
The Painted Desert Inn is a prominent landmark within the Painted Desert. Herbert Lore, a local homesteader, began constructing the two-story inn in 1920. Initially called the "Stone Tree House," the inn was built with a significant amount of petrified wood. Lore registered it as a business in 1924. For nearly twelve years, Lore operated the inn as a tourist attraction. Visitors could dine in the lunchroom, purchase Native American arts and crafts, and enjoy refreshments in the downstairs taproom. Rooms were available for $2-4 per night. Lore also offered guided tours through the Black Forest in the Painted Desert below. The inn was an isolated oasis, so an onsite lighting plant was built to supply electricity. Water was transported from Adamana, ten miles south on the Puerco River.
The inn was constructed in the Pueblo Revival style, using wood and native stone. Flagstone terraces surrounded by low walls offered panoramic views of the desert. The building’s stone walls are over two feet thick and finished with textured earth-toned stucco. Multiple flat roofs with parapets give the inn its varied massing, and Ponderosa Pine logs pierce the walls, adding play between light and shadow.
In 1932, over 53,000 acres were added to the Petrified Forest National Monument, including much of the Painted Desert. In 1936, the Petrified Forest National Monument purchased the Painted Desert Inn. Work quickly began on updating the inn’s electrical, plumbing, and heating systems. Guest rooms, a new entryway, a dining room, and a shaded porch were added to the original structure, as well as stained glass ceiling panels, hammered tin chandeliers, and hand-carved furniture.
During the Dust Bowl era, thousands of people migrated west on Route 66 seeking a better life. The Grapes of Wrath documented this era, including scenes filmed at the Painted Desert Inn.
In 1940, the inn opened under the management of the Fred Harvey Company. The Harvey Girls provided service in the dining room. In 1947, Mary Jane Colter renovated the facility, creating a new interior color scheme and overseeing other changes. New plate glass windows were installed to capitalize on the surrounding landscape. Hopi artist Fred Kabotie painted murals reflecting Hopi culture. In 1948, the Painted Desert Inn became the park’s northern headquarters.
After World War II, Route 66 became busier. For many, a stop at the Petrified Forest National Park and the Painted Desert Inn was a must.
The inn declined over the next decade. In 1963, it closed. The building sat abandoned for the next 27 years and was nearly demolished in 1965 and again in 1975. A public campaign helped save the building, which was listed in the National Register of Historic Places in 1976. In 1987, it became a National Historic Landmark.
The Painted Desert Inn reopened in 2006 after restoration. It now appears as it would have in 1949. Functioning as a museum and bookstore, visitors can again experience the architectural details and walls of the Painted Desert Inn.
Puerco Pueblo
During the Pueblo I Era, most sites were single-family homes. But as soils became exhausted, many sites were abandoned by 1250 A.D. This was likely the case with the Puerco Pueblo in today’s Petrified Forest National Park. Overlooking the Puerco River, this 100-room pueblo, built around 1250, surrounded an open plaza. The rooms had no windows or doors, but each could be entered by climbing a ladder and descending through a hole in the roof. At its peak, as many as 200 people lived in the pueblo.
The pueblo stood one story high, with 2 to 3 rows of connected rooms. Within the plaza were several rectangular ceremonial kivas. The village was a lively center. The people were thought to have joined with their ancestors, the Hopi or Zuni people.
At Puerco Pueblo and many other sites within the park, petroglyphs have been carved on rock surfaces.
The pueblo is near the middle of the park. A trail to the pueblo is a short 0.3-mile loop from the Puerco Pueblo parking area. Petroglyphs can be viewed along the south end of the trail.
Old Route 66
Route 66 paralleled the railroad in Arizona.
In the Petrified Forest National Park, old Route 66 bisected the main park highway. In the late 1950s, a new alignment bypassed the route. Today, the route is marked only by the remnants of the raised roadbed, weathered telephone poles, and a park exhibit.
Petrified Forest National Park is the only park in the National Park System containing a section of Historic Route 66.
Bypassed in the late 1950s, today’s route is marked only by the remnants of the raised roadbed, a line of telephone poles, and a park exhibit marking the intersection.
Other places within the Petrified Forest National Park are listed on the National Register of Historic Places, including the Newspaper Rock Petroglyphs, Archaeological District, and Twin Buttes Archaeological District.
The Painted Desert Visitor Center provides information, book sales, exhibits, and restrooms.
The Rainbow Forest Museum provides exhibits of petrified wood, fossils, displays of prehistoric animals, information, book sales, and restrooms.
Travel through the park is by private vehicle, bicycle, motorcycle, or commercial tour only. The park road, parking lots, and pull-outs suit recreation vehicles. Off-road vehicle travel is not allowed. The park does not have campground facilities, and overnight parking is not allowed.