Prospect Dam (Arizona)

{{Short description|Former lava dam in the Grand Canyon of Arizona}}

{{1R|date=July 2016}}Prospect Dam is a former lava dam in the Grand Canyon of Arizona, United States. It was the oldest and tallest of several former lava dams in the Grand Canyon.{{Cite journal |last=Dalrymple |first=G. Brent |last2=Hamblin |first2=W. K. |date=1998-08-18 |title=K-Ar ages of Pleistocene lava dams in the Grand Canyon in Arizona |url=https://pnas.org/doi/full/10.1073/pnas.95.17.9744 |journal=Proceedings of the National Academy of Sciences |language=en |volume=95 |issue=17 |pages=9744–9749 |doi=10.1073/pnas.95.17.9744 |issn=0027-8424|pmc=21407 }} It was formed about 1.2 million years ago as lava flowed down the walls of the Grand Canyon, and temporarily stopped the flow of the Colorado River.{{cite book |last=Schmidt |first=Jeremy |year=1993 |title=Grand Canyon National Park: A Natural History Guide |url=https://books.google.com/books?id=CAVQJfipgB4C&pg=PA34 |publisher=Houghton Mifflin |pages=34–36 |isbn=9780395599327 |access-date=September 4, 2021}}