Editing Grand Canyon (section)

==Geography==
[[File:GrandCanyon.NASA.2014.jpg|thumb|Image of the Grand Canyon and surrounding area taken from the [[International Space Station]]]]
[[File:Grand Canyon from air.JPG|thumb|upright|The Grand Canyon from an airplane, with the Colorado River visible]]
[[File:GrandCanyon27June2017.tif|thumb|Grand Canyon, Arizona, Nevada, [[Lake Powell]] to [[Lake Mead]], June 27, 2017, [[Sentinel-2]] true-color satellite image. Scale 1:450,000.]]

The Grand Canyon is a [[river valley]] in the [[Colorado Plateau]] that exposes uplifted [[Proterozoic]] and [[Paleozoic]] [[Stratum|strata]],<ref name="Ranney">{{cite journal |last1=Ranney |first1=Wayne |title=A pre–21st century history of ideas on the origin of the Grand Canyon |journal=Geosphere |date=April 2014 |volume=10 |issue=2 |pages=233–242 |doi=10.1130/GES00960.1 |bibcode=2014Geosp..10..233R |language=en |issn=1553-040X |doi-access=free}}</ref> and it is also one of the six distinct physiographic sections of the Colorado Plateau province.<ref name="Leydsman McGinty">{{cite book |last1=Leydsman McGinty |first1=Ellie I. |last2=McGinty |first2=Christopher M. |editor-last1=Banner |editor-first1=R. E. |editor-last2=Baldwin |editor-first2=B. D. |editor-last3=Leydsman McGinty |editor-first3=Ellie I. |title=Rangelands resources of Utah |chapter=Physiography of Utah |date=2009 |publisher=Utah State University Cooperative Extension Service |location=Logan, Utah, USA |pages=24–28 |url=https://extension.usu.edu/rangelands/ou-files/RRU_Section_Three.pdf |archive-url=https://web.archive.org/web/20220826162151/https://extension.usu.edu/rangelands/ou-files/RRU_Section_Three.pdf |archive-date=August 26, 2022 |url-status=live |access-date=June 23, 2022}}</ref> Even though it is not the deepest canyon on land in the world ([[Kali Gandaki Gorge]] in Nepal is much deeper<ref>{{cite web |last1=Montmoli |first1=C |title=A geological journey through the deepest gorge on Earth: the Kali Gandaki valley section, west-central Nepal |url=https://www.researchgate.net/publication/264996830 |website=ResearchGate.net |access-date=July 27, 2021 |archive-date=May 30, 2024 |archive-url=https://web.archive.org/web/20240530070307/https://www.researchgate.net/publication/264996830_A_geological_journey_through_the_deepest_gorge_on_Earth_the_Kali_Gandaki_valley_section_west-central_Nepal |url-status=live }}</ref>), the Grand Canyon is known for its visually overwhelming size and its intricate and colorful landscape. Geologically, it is significant because of the thick sequence of ancient rocks that are well preserved and exposed in the walls of the canyon. These rock layers record much of the early geologic history of the North American continent.<ref name="Witze"/>

Uplift associated with mountain formation later moved these sediments thousands of feet upward and created the Colorado Plateau. The higher elevation has also resulted in greater precipitation in the Colorado River drainage area, but not enough to change the Grand Canyon area from being semi-arid.<ref>{{cite journal |last1=Marlatt |first1=William |last2=Riehl |first2=Herbert |title=Precipitation regimes over the upper Colorado River |journal=Journal of Geophysical Research |date=December 15, 1963 |volume=68 |issue=24 |pages=6447–6458 |doi=10.1029/JZ068i024p06447 |bibcode=1963JGR....68.6447M}}</ref> The uplift of the Colorado Plateau is uneven, and the [[Kaibab Plateau]] that the Grand Canyon bisects is over {{convert|1000|ft|m|spell=in}} higher at the North Rim than at the South Rim. Almost all runoff from the North Rim (which also gets more rain and snow) flows toward the Grand Canyon, while much of the runoff on the plateau behind the South Rim flows away from the canyon (following the general tilt).<ref name="Witze"/> The result is deeper and longer tributary washes and canyons on the north side and shorter and steeper side canyons on the south side.<ref name="Kiver">{{cite book |last1=Kiver |first1=Eugene P. |last2=Harris |first2=David V. |title=Geology of U.S. Parklands |date=June 15, 1999 |publisher=John Wiley & Sons |isbn=978-0-471-33218-3 |url=https://books.google.com/books?id=S0zDQWiFuvkC&pg=PA406 |access-date=June 23, 2022 |language=en |archive-date=June 23, 2022 |archive-url=https://web.archive.org/web/20220623134709/https://books.google.com/books?id=S0zDQWiFuvkC&pg=PA406 |url-status=live }}</ref>{{rp|406}}

Temperatures on the North Rim are generally lower than those on the South Rim because of the greater elevation (averaging {{convert|8,000|ft|m|disp=or|sp=us}} above sea level).<ref name=NPSnatsci/> Heavy rains are common on both rims during the summer months. Access to the North Rim via the primary route leading to the canyon ([[Arizona State Route 67|State Route 67]]) is limited during the winter season due to road closures.<ref name=off-season(jump-link)>{{cite web |title=Winter on the North Rim (off-season) |url=http://www.nps.gov/grca/planyourvisit/hours.htm#CP_JUMP_538881 |work=Operating Hours & Seasons |publisher=National Park Service; US Dept. of Interior |access-date=January 21, 2013 |url-status=live |archive-url=https://web.archive.org/web/20110303012942/http://www.nps.gov/grca/planyourvisit/hours.htm#CP_JUMP_538881 |archive-date=March 3, 2011}}</ref>