The Grand Canyon is a 5.5-hour drive from Las Vegas. It's far but worth it if you've never been! The South Rim (more developed and far more visited than the Northern Rim) is open 24 hours a day, 365 days a year, although they recommend avoiding winter months due to inaccessibility because of snow. Some days are a bit overcast and/or foggy, and this may affect the quality of photos you take.
The canyon, created by the mighty Colorado River, is huge and absolutely breathtaking! It averages 4,000 feet deep for its entire 277 miles. It is 6,000 feet deep at its deepest point and 15 miles at its widest. Many people find it enjoyable to hike down the canyon, but keep in mind to not try to hike all the way down and back in the same day, and try to avoid the afternoon hottest hours! As we were told, the majority of victims rescued from the Grand Canyon are young, healthy males between the ages of 18 and 40 who attempted to hike to the river and back in one day. Just 2 weeks prior to our visit one young college guy from the U.K. had died while attempting it--it's serious business, so take heed!
On a lighter note, there are free park ranger-led talks several times a day, and these are one of the best parts of the visit! The park rangers know so much and can add a lot of interesting tidbits to the journey. They take their job very seriously and are very committed to the canyon and its preservation. We were told the story of one Native American canyon guide who traveled all the way to Switzerland and donned his native attire to lobby a multinational company there not to develop the canyon for some industry they were considering. If you see the photo below, our guide was even wearing a long-sleeve wool uniform in the hot July temperatures! He explained to us that since he had tattoos on his arms from his youth, the national park felt that he should keep them covered while he was on duty to show a more professional image, so he had to wear the long-sleeve version of their uniform, and to keep the uniform even, he had to wear it with the wool winter pants instead of the cooler summer pants because those only match with the short-sleeve uniform shirt. So you can see how dedicated he was to suffer in that heat because of their rules!
Within the Grand Canyon Village area they offer free shuttle services, so you can see different parts of the canyon, visit the shops, restaurants etc. When you first enter at the park entrance station (either North or South Rim), you are given a copy of "The Guide," which is the park's newspaper. It lists the various parking areas, ranger programs, and visitor facilities.