The Monongahela tribe of Native Americans is believed to be descended from the earliest group of human inhabitants of Western Pennsylvania. Archaeologists believe these people to be immigrants from Asia who walked across the land bridge from Siberia to Alaska. Some sites in Western Pennsylvania, most notably the Meadowcroft Rock Shelter, are believed to date back as long as 12,000 to 15,000 years.
The Monongahela tribe eventually developed canoes to travel along the region's rivers, began to cultivate crops, and built villages, some of which consisted of as many as 50-100 structures. These people also traded with other tribes who in turn traded with Europeans, but the Monongahela tribe seems to have vanished mysteriously some time during the 1620s or 1630s before ever having significant direct contact with Europeans. Many believe this to be the result of the spread of European diseases. Others believe that most of the tribe were killed by or assimilated into either the Iroquois or the Delaware tribes during war. Still others claim that two massive droughts, one from 1587-1589 and another from 1607-1612, drove the Monongahela from the region in search of a more habitable area.
There have been many Monongahela burial sites and villages unearthed during the development of Western Pennsylvania and Northern West Virginia from the latter half of the 20th century to the present day.
The Monongahela culture extended in the area of the upper Ohio River system that includes the Monongahela, Youghiogheny and Casselman tributary rivers from A.D. 900 into 1600s. Their region is of western Pennsylvania and the adjoining areas of eastern Ohio, West Virginia, and western Maryland. Nearly four hundred sites have now been recorded. The Monongahela culture was contemporaneous to the bordering Fort Ancient culture on the Ohio Valley. "The Fort Ancient-influenced Monongahela complex [Fitting 1978: 55] is a Late Woodland horizon that coincides with the Mingo homeland and distinguishes it from the League homeland. Monongahela villages originated on flood plains, but, by AD 1250, they had migrated to the watershed highlands and often on gaps between ridges. Their houses were small and circled around a central plaza. It was at this time scholars figure there was feuding among villages.
Monongahela houses were oval to round shaped and were built within stockaded villages. Some of these palisaded village's entry often had a maze-like entryway that overlapped the stockaded outer walls. Further differing from Fort Ancient, some entrances were covered. These led to a central plaza surrounded by houses made of slippery elm and poles within the stockade. Some of the villages had elevated observation platforms. Charnel houses have been found in the larger villages. Black bear masks have been found in the few graves showing an indication of a rank. Of the average adult burials, it is not clearly understood where they might have been burried. Child burials were sometimes inside the village and sometimes under the house contrasting Andaste burials which were outside their palisaded village found east of the Allegheny Mountains stemming from A.D. 1450/1550. By AD 1450, petal-shaped attachments to their houses became common and used for storage or perhaps a smokehouse. Monongahela pottery and tools were well crafted to include decorated smokers' clay pipes. Glass trade beads have been found at some villages although there is no record of European contact. The Monongahela Culture was an otherwise advanced culture seeing no Renaissance Metallurgy.
Like its sister culture and neighbor, Fort Ancient, these made a leap in agriculture with seed from Mesoamerica that had been worked through their ancestral trade network.(Dragoo) They traded with the east coast agriculturists and the other fort builders. Advances in tobacco and hemp braid crops were parallel with their distinctive ability with reinforced tempered clay loop-handle cooking pots. Richard Hakluyt is one of the earlier who report on Native American foods of the mid Atlantic coastal people of whom they also traded with. Sea shells from the mid-Atlantic have been found in some sites. "Both groups (Monongahela & Fort Ancient) were predominantly farmers, basing their innovative, though short-lived, lifestyle on crops that had worked their way north from earlier South American and Mexican cultures", quoting Margaret M. Nava, Wonderful West Virginia magazine.
This late perhistoric culture peaked about A.D. 1300. The colder weather that followed this time caused inter-tribal battling over food according some scholars. Their Central American vegetables did not weather well during this colder period causing the food shortages to a grown populace of these farmers. Studies do show that the culture began failing to poor health conditions. There were about 100 members in an average village and some had much more to feed.
The Monongahela farming culture was progressively disappearing before the time the Iroquois League invaded the Allegheny Plateau through to the Lake Erie region. Neither the Monongahela nor its sister farming culture acquired the arquebus as a few other coastal cultures saw this arrival in the 16th century. About the year of AD 1635, it appears that a group of Monongahela refugees resettled in south-central Virginia at Halifax County (Wells 2002). It is not clear if the Iroquois, Piedmont Siouan or Algonquian dialects assimilated these people while the rising Petun, Mingo, Nation of Cat, Andaste, Shawnee, Miami, Seneca, Neutral Nation and farther still perhaps ancient Tuscarora, Notowega, Meherrin and Delaware groups appeared as mentioned above, but, the "Monongahela" culture did not survive.