T Grand Canyon steep-sided gorge carved y Colorado River U.S. state Arizona. I largely contained within Grand Canyon National P — first national parks United States. President Theodore Roosevelt major proponent preservation Grand Canyon area, visited numerous occasions enjoy scenery.

T longstanding scientific consensus canyon created y Colorado River period x million years, research released 2008 suggests longer 17 million y p. T canyon 277 miles (446 ) long, ranges width 4 18 miles (6.4 29 ) attains depth (1.6 ). Nearly billion years Earth's history exposed Colorado River tributaries their channels through layer after layer while Colorado Plateau uplifted. T "canyon started west, another formed east, broke through single majestic earth x million years g. T merger apparently occurred where river today, coming north, bends west, known Kaibab A."

During prehistory, inhabited y Native Americans built settlements within canyon y caves. T Pueblo people considered Grand Canyon ("Ongtupqa" Hp language) y pilgrimages . T first European known viewed Grand Canyon García López Cárdenas Spain, arrived 1540. I 1869, Major J Wesley Powell, -armed Civil W veteran thirst science adventure, first recorded journey through canyon Colorado River. Powell referred sedimentary units exposed canyon "leaves great story book".

T Grand Canyon massive Colorado Plateau exposes uplifted Proterozoic Paleozoic strata x distinct physiographic sections Colorado Plateau province. T Grand Canyon unmatched throughout world vistas offers visitors . I deepest canyon world — Cotahuasi Canyon (11598 3535 ), Colca Canyon (10499 3200 ), Arequipa, P Hell's Canyon Oregon-Idaho border deeper — Grand Canyon known overwhelming intricate colorful landscape. Geologically significant because thick sequence ancient rocks beautifully preserved exposed walls canyon. These layers record early geologic history North American continent.

Uplift associated mountain building events later moved these sediments thousands upward created Colorado Plateau. T higher elevation resulted greater precipitation Colorado River drainage area, enough change Grand Canyon being -. T uplift Colorado Plateau uneven, north-south trending Kaibab Plateau Grand Canyon bisects thousand higher North R (about 1,000 ft/300 ) South R. T Colorado River flows curve around higher North R p Kaibab Plateau closer South R p plateau explained y asymmetry. I Lucchitta U.S. Geological Survey first suggested that, Colorado River developed before significant erosion region, naturally found y across around Kaibab Uplift y following "racetrack" p south highest p plateau. Almost runoff North R (which g ) flows toward Grand Canyon, while runoff plateau behind South R flows y canyon (following general ). T result deeper longer tributary washes canyons north shorter steeper canyons south .

Temperatures North R generally lower South R because greater elevation (averaging 8,000 ft/2,438 above level). Heavy rains common during summer months. Access North R primary route leading canyon (Arizona State Route 67) limited during winter season closures. Views North R g better impression expanse canyon those South R.

Tourism Information

Grand Canyon National P world’s premier natural attractions, attracting about million visitors p y. Overall, 83% United States: California (12.2%), Arizona (8.9%), Texas (4.8%), Florida (3.4%) N Y (3.2%) represented p domestic visitors. Seventeen percent visitors outside United States; prominently represented nations United Kingdom (3.8%), Canada (3.5%), Japan (2.1%), Germany (1.9%) T Netherlands (1.2%).

Things Grand Canyon

Aside casual sightseeing South R (averaging 7000 (2100 meters) above level), whitewater rafting, hiking running especially popular. T floor valley accessible y foot, muleback, y upriver. Hiking river p y discouraged y p officials because distance, steep rocky trails, change elevation, danger exhaustion higher temperatures bottom. Rescues required annually unsuccessful --river-- travelers. Nevertheless, hundreds experienced hikers complete p every y.

Camping North South R generally restricted established campgrounds reservations highly recommended, especially busier South R. A overnight camping below requires backcountry permit Backcountry Country Office (BCO). E y Grand Canyon National P receives approximately 30,000 requests backcountry permits. T p issues 13,000 permits, close 40,000 people p overnight. T earliest permit application accepted first month, months prior proposed start month. Applying allowed improve y chances obtaining overnight backcountry permit dates y choice.

Tourists wishing vertical perspective board helicopters small airplanes L Vegas Phoenix canyon flyovers. Scenic flights longer allowed y within 1500' within national p because 90 crash. T aerial video footage below filmed 1984. However, helicopter flights Havasupai Hualapai Indian Reservations within Grand Canyon (outside p boundaries). Recently, Hualapai Tribe opened glass-bottomed Grand Canyon Skywalk their property, Grand Canyon W. T Skywalk mixed reviews since y accessible y driving 14- (23 ) road, costs minimum $85 total reservation fees, package admission Skywalk itself cameras permitted Skywalk y . T Skywalk located 242 miles South R National P. My people mistake p y Hermit's R location Skywalk. T however incorrect information. However, views canyon South R better y g Skywalk, benefit common mistake.

S places Great Views

Lipan Point promontory located South R. T point located Grand Canyon Village along Desert V Drive. There parking visitors drive along Canyon's service routinely stops point. T trailhead Tanner Trail located j before parking . T Lipan Point shows array strata Unkar Creek inner canyon.

Perhaps heart-stopping canyon Toroweap Overlook (Tuweep) situated 3000 vertical above Colorado River, about 50 miles downriver South R 70 upriver Grand Canyon Skywalk. T region — “O remote United States” — according National P Service, reached y y three lengthy tracks, start S. George, Utah, Colorado Cy Pp Spring National Monument ( Arizona). These roads traverse wild, uninhabited 97, 62 64 miles respectively. A visit challenging, rewarding. T P Service manages primitive values , therefore, improvements services minimal.