Daniel left for work early in the morning, on Monday, September 3, 2018, from his mother's house in Glendale, Arizona. His vehicle was later found abandoned on Saturday, September 8, 2018 at Tonto National Forest, approximately 2 miles north of the Seven Springs camping area.

Jonghyun Won was last thought to be in Grand Canyon Sept. 17, 2017. His vehicle was sighted near New Hance Trailhead and found abandoned at Moran Point.

Butler was last seen in Tusayan, Arizona on August 1, 2017. He is from Ohio and had driven to Arizona to visit the Grand Canyon.

Roberts was last seen in Grand Canyon National Park in Arizona. He and a group had started a nine-day hike on the Shivwits Plateau in a remote portion of western Grand Canyon, when he got separated from the others.

Kosden, 69, was reported missing Sept. 19, 2015, after he failed to return home after a planned trip to southeast Cochise County. His vehicle was found abandoned at Rustler Park with a parking pass, which showed he entered the campground Sept. 13.

Gallegos left her father’s Lakeside, Arizona residence on May 20, 2010. She got into a vehicle with two men, one of whom was Jacob Mata, and they went to Phoenix, Arizona to purchase heroin.

After the group bought the heroin, one of the men left and another woman joined Gallegos and Mata. They were on the way to Show Low, Arizona on State Route 87, when they got lost and ended up on a Forest Service road in the White Mountain Apache Forest.

Gallegos left her father’s Lakeside, Arizona residence on May 20, 2010. She got into a vehicle with two men, one of whom was Jacob Mata, and they went to Phoenix, Arizona to purchase heroin.

After the group bought the heroin, one of the men left and another woman joined Gallegos and Mata. They were on the way to Show Low, Arizona on State Route 87, when they got lost and ended up on a Forest Service road in the White Mountain Apache Forest.

Kirchner was last seen in Coconino County, Arizona in early April 2007. He worked as a physicist back in Germany and had visited the United States many times before. He was hiking a remote section of the Navajo Reservation. He’s an experienced hiker who was in good physical condition and hiked extensively in the Colorado Plateau area.

Justin was last seen in Kaibab National Forest in Arizona on June 29, 2001. He and some older friends had gone into to an area a few miles south of Grand Canyon National Park and five miles west of Moqui Lodge. Authorities believe he had been partying and was under the influence of drugs, possibly methamphetamine.

Miller was last seen leaving for a two-and-a-half-day hiking trip in Sedona, Arizona on May 19, 1998. He is an experienced hiker and was employed by the Sedona Forest Service at the time he went missing. Miller never returned from his trip and has not been seen again. He is believed to have become lost or injured in the area, possibly by falling on slippery terrain, but his body has never been found.

It’s been nearly 30 years since ranger Paul Fugate disappeared while patrolling the wilds of Chiricahua National Monument. What happened to him remains a mystery to this day.

When a ranger on solo patrol in a remote area of a national park fails to return, the event rarely becomes what you’d call a true disappearance. Search and rescue procedures being as good as they are, a ranger who’s lost, stranded, or injured can reasonably expect to be rescued in pretty short order. Even if the missing person is no longer alive, remains are typically found within a few days, weeks, or months.