[1] During the summer of 1876, Hill joined a survey crew headed to the Rolling Plains between the eastern edge of the Llano Estacado and Fort Griffin, Texas.

This land of reddish-brown sediments and rock has been carved by years of erosion, leaving behind scenic mesas and buttes that preserve clues to the region's geologic past.

In 1877, at the age of 19, Hill accepted an offer to work as a cowboy driving a large herd of cattle from Uvalde, Texas, to Dodge City, Kansas.

The cattle drive took many months, during which time he learned to live outdoors for extended periods and developed frontier skills that proved valuable in his later years, as he worked as a field geologist.

He then ordered, through his local drug store, a copy of the Manual of Geology by James Dwight Dana, one of the leading geologists in North America.

[2] He traversed portions of the state underlain by Cretaceous deposits accompanied by William Fletcher Cummins of Dallas, another geologist who would prove to be an influential figure in early Texas geological study.

Publication of The topography and geology of the Cross Timbers and surrounding regions in Northern Texas, established Hill as the first to recognize the two-fold subdivision of the Cretaceous system.

[10][11] His stratigraphic studies and investigations of underground and artesian waters led to improvements of vast areas of farm and ranch land and served as the foundation for future petroleum exploration.

[15] Near the turn of the century, Hill conducted studies in the West Indies and the Isthmus of Panama, areas he considered fundamental to understanding the geological evolution of North America.

[17] He mapped the destruction area and wrote the first account of the devastating effects of dense, fast-moving clouds of hot gas and rock known as pyroclastic flows or nuée ardente, previously unknown to vulcanologists.