My Great Uncle Patrick Carnes was 86 when he and his dog Lucky vanished off a stretch of I-80 in Nevada often referred to as "The Big Lonely." Despite his age, my Uncle Pat often drove with his dog from Reno, Nev., where he lived to visit his family in Ohio. On April 13, 2011 he was driving on the interstate near the town of Wells, Nev., at 9 p.m. on his return trip from Ohio when he was pulled over and warned about an illegal lane change.

During the conversation he told the state trooper he had been following a trucker to the next town where he planned to get a room for the night. After viewing the trooper’s dash cam video, it appeared as if my uncle, a former truck driver himself, was following directly behind a tractor trailer rig, which police could not identify. That's the last time anyone ever saw Pat or Lucky.

The next morning someone called police to report an abandoned vehicle on I-80 at the Pumpernickel Valley off-ramp (exit 205). There was no one in the car, but Pat's luggage, wallet, and checkbook were still inside, which ruled out a robbery.

Police didn't suspect a crime until several days later when they went to Pat's apartment to check on him and found two of his sons who were also looking for Pat. Despite between 600-700 hours of canine searches, ATV and Jeep off-road searches, investigations by ground teams, and several aerial flights over the area, the searches failed to turn up any evidence.

My Uncle Pat was old school. He didn't use credit cards, and he didn't have a cell phone. His lack of a digital footprint made it harder to track his movements, but several of my family members who work in law enforcement joined the search, reviewed traffic tapes, and consulted with investigators to no avail.

What's even more upsetting is that Pat isn't the first person to go missing at exit 205. In 2006, 62-year-old Judith Casida disappeared at the same location, her car parked in a similar manner. While there has been speculation of an alleged long-haul I-80 serial killer, no trace of Casida or my Uncle Pat have ever been found, and police haven't identified any suspects in either case.

The D.B Cooper case is pretty legendary, and has been the subject of songs, movies, documentaries, and folklore since the day it happened. According to the website Crime Documentary, on Nov. 24, 1971 a man dressed in a suit and tie hijacked a Northwest Orient flight bound for Seattle, Wash. from Portland, Ore. The hijacker claimed to have a bomb, and he demanded $200,000 in cash, and four parachutes.

"Once he got his ransom, the man jumped into the night, never to be seen again," Crime Documentary noted. "In the more than 45 years since the epic heist, the FBI has looked at over a thousand potential suspects, but the questions remain: Who is D.B. Cooper? Did he die? Did he live? And is he still out there?"

While the case remains the only unsolved aviation crime in U.S. history, a man claiming to be the brother of D.B. Cooper contacted the late writer and director Nora Ephron, according to a story in New York Magazine. The FBI investigated, but could not determine if the man's story was true.

Despite working on the case for more than 45 years, no evidence of the hijacker or the ransom money was ever found. Many thought Cooper surely perished due to temperatures that were at least 70 degrees below zero when he leapt from the plane, but no remains were discovered. In 2016, the FBI officially suspended the investigation.

"Although the FBI will no longer actively investigate this case, should specific physical evidence emerge — related specifically to the parachutes or the money taken by the hijacker — individuals with those materials are asked to contact their local FBI field office," the FBI noted in a press release.

The case of missing teen Nicholas Barclay, who went missing from Texas in 1994 when he was 13, is even more tragic because a French con-man, Frédéric Bourdin, assumed the missing teen's identity three years later, and lived with his family as their long-lost son.

Bourdin is the subject of a 2012 documentary appropriately titled The Imposter. In the film he details how he wandered into a European police station and claimed to be a missing boy from America. With a history of impersonating others to gain access to food, clothing, and shelter, Bourdin convinced not only authorities that he was the missing Texas teen, he convinced Barclay's family, too.

Despite speaking with a French accent, clearly being much older than Barclay, and having a different hair and eye color, Bourdin was so convincing he kept up the ruse for months before people became suspicious. Bourdin went to jail for impersonating Barclay, but the case of what actually happened to the 13-year-old has never been solved, and Barclay is technically still missing.

Maura Murray, a 21-year-old nursing student, vanished from the side of the road in Haverhill, N.H., in 2004. A podcast titled Maura Murray Missing delves into the mysteries about why the college student drove three hours from her dorm in Amherst, Mass., to the White Mountains of New Hampshire and disappeared.

"At approximately 7:30 p.m. her car was involved in a single car, non life threatening accident at a hairpin turn on the dark and desolate Route 112," the podcast description explained. "The few witnesses who spoke with police said she denied their assistance. She was gone without a trace before the police showed up approximately 10 minutes later. She has never been seen or heard from since."

A documentary, The Disappearance Of Maura Murray, by Lance Reenstierna and Tim Pilleri, is currently in production about the case. "Maura wanted to get away from something in her life, that we know," the filmmakers wrote on their website. "In the 10 years following the accident and her disappearance, a frenzy of theories — from the rational to the extremely far-fetched — surfaced in the online community." ... "Our documentary is focused on how this one incident, performed by one young woman trying to figure life out, borne this ripple-effect."

Jennifer Kesse was reported missing from Orlando, Fla. on Jan. 24, 2006 when she failed to show up for work, according to JenniferKesse.com. The website details that it appears that her bed had been slept in, and her shower used, and police speculated that the 24-year-old woman disappeared sometime in between leaving her apartment around 8 a.m. and when she should have arrived at work. She has never been seen again.

Kesse's car was found Jan. 26 about a mile from her condo, and security footage shows a man driving the car, though the footage was too grainy to make an identification.

Two men, Shaun Gurd and Scott Jamison of Gainesville, Fla., became interested in the case and started a podcast titled Unconcluded to explore possibilities of what happened to Kesse, according to the Orlando Sentinel. The podcast has sparked renewed interest in the case, which has made little progress in 11 years.

"How have we not progressed in 11 ½ years to at least a direction?" Jennifer's father Drew Kesse told the Orlando Sentinel. "She vanished. How is that?"

While there are no new leads, Kesse's father meets with investigators twice a year to discuss the case.

Asha Degree was just 9 years old when she vanished from her bed in North Carolina during the early morning hours of Valentine's Day in 2000. According to the Charlotte Observer, Degree's family last saw her in her bed at 2:30 a.m., and drivers reported seeing her walk along N.C. 18 in Shelby, N.C., 90 minutes later.

One year after her disappearance the child's backpack was found buried on the same road. Stephanie Faris noted on the Mystery Monday series on her blog that the backpack "contained several sets of clothes, including her basketball uniform, as well as some photos of her family. It is believed that she packed the bag herself and snuck out of the house in the rain that morning ... but why?"

In 2016, police released a new detail. According to the Charlotte Observer a witness reported seeing Degree get into an early-1970s Lincoln Mark IV or Ford Thunderbird, dark green, with rust around the wheel wells.

Degree's story is also detailed in the Thinking Sideways Podcast. Additionally, the Charley Project noted that Degree's class was reading the book The Whipping Boy by Sid Fleischman about two children who run away, but return safely. It's not know whether the book is a factor in the disappearance.

Maria Des Los Angeles Martinez went to a babysitting job on Oct. 13, 1990 in Phoenix, Ariz., and never came back. According to the Charley Project, Martinez called a local radio station to advertise her babysitting services on Oct. 12. A man reportedly responded to the ad, and agreed to pick up the teen the next morning at her home at 10 a.m. for a babysitting gig.

It was reported that Martinez called her parents shortly after she left home and asked them to pick her up. Before she could give them the address the line was disconnected, and Martinez was never seen or heard from again. Police were never able to identify the man who called the station.