Authorities searching for Nancy Guthrie are bound to run into serious hurdles, given that the areas surrounding her home are treacherous, vast and filled with challenging terrain.
The 84-year-old mother of Today show host Savannah Guthrie vanished from her home in Tucson, Arizona, between the night of January 31 and the morning of February 1.
Nancy lives in the Catalina Foothills, a community northeast of downtown Tucson replete with single-family homes nestled in high-elevation areas and desert landscapes.
So far, local police and the FBI have conducted rigorous search and rescue efforts by ground and air. These efforts are complicated by the fact that much of southern Arizona has uneven topography, limited visibility at times and rapid temperature changes.
It has also been revealed that Nancy had serious medical complications, including heart issues she needs medication for. Most crucial is that she has limited mobility, according to police and her family, making it virtually inconceivable that she left on her own.
'At this point, investigators believe she was taken from her home against her will, possibly in the middle of the night. Taken against her will includes possible kidnapping or abduction,' Pima County Sheriff Chris Nanos said. 'She couldn't walk 50 yards by herself.'
The Catalina Foothills is a mix of private residential property and land that is managed by state and federal agencies. These include Saguaro National Park and parts of the Coronado National Forest through the Santa Catalina Mountains.
Much of the public land is rugged and unforgiving, marked by rocky slopes, tight canyons and desert vegetation, including creosote, palo verde, mesquite, cholla cactus and bunch grasses.
Nancy Guthrie, the 84-year-old mother of Today show host Savannah Guthrie, disappeared from her home in Tuscon, Arizona, last weekend
Her home (pictured on Friday) is nestled within the Catalina Foothills, a suburban community northeast of downtown Tucson
The Catalina Foothills contains rugged, uneven terrain and crisscrossing trails that make it hard to search. Additionally, temperatures fluctuate in the desert landscape, further complicating the mission of search and rescue teams
Vast swaths remain undeveloped, crisscrossed by only a handful of roads and a web of remote trails. It's also quite easy to make wrong turns on trails, many of which blend with untamed terrain.
On top of that, areas of this land can have snow falling at one part of the day, then turn brutally hot. In February, temperatures can sink to freezing after the sun sets.
At night, coyotes can be heard howling in the desert. It is also possible to run into mountain lions, black bears or venomous western diamondback rattlesnakes.
For a well-provisioned, experienced hiker, these conditions, though harsh, can easily be overcome. But prolonged searches in these areas will inevitably grow challenging for investigators.
It has been roughly a week since Nancy disappeared. On the evening of January 31, she traveled to a relative's home for dinner and was dropped back off that night.
At 1.47am on February 1, Nancy's doorbell camera was disconnected and removed and roughly 40 minutes later, her pacemaker was unpaired from her phone.
After Nancy failed to show up to church, the family called 911. Police arrived at around 12.15pm and found blood on the porch they later confirmed belonged to Nancy.
Given her lack of mobility, investigators are operating under the assumption that someone or a group of people took her in the middle of the night against her will.
Nancy's home is 70 miles from the United States-Mexico border
A wide array of law enforcement agencies have come together to collaborate on finding Nancy. Tucson police (pictured outside the home), the Pima County Sheriff's Department and the FBI are on the case
Pima County Sheriff Chris Nanos believes Nancy is still alive and was taken from her home against her will
On Friday, Pima County Sheriff Chris Nanos told reporters he believes she is out there and was taken against her will.
'What I believe is that Nancy was removed from her home against her will, and that we need to find her. That's what I believe. She's still alive,' Nanos said. 'I believe that I have no choice until something shows me, a piece of physical evidence shows me that that's different.'
In the wake of two ransom letters being sent to news outlets, Nancy's children posted a video on Wednesday to Savannah Guthrie's Instagram pleading with her purported kidnappers to make contact with them.
An emotional Savannah sat between her sister Annie and brother Camron as she delivered her message.
'Our mom is a kind, faithful, loyal, fiercely loving woman of goodness and light. She's funny, spunky and clever. She has grandchildren that adore her and crowd around her and cover her with kisses,' Savannah said.
'She is 84 years old. Her health, her heart is fragile. She lives in constant pain. She is without medicine; she needs it to survive. She needs it not to suffer,' she added.
Savannah then said to the potential kidnappers that 'we are ready to talk' but wanted proof that they weren't potentially using fraudulent images of her.
'We live in a world where voices and images are easily manipulated. We need to know, without a doubt, that she is alive and that you have her. We want to hear from you and we are ready to listen. Please, reach out to us,' she said through the tears.
Savannah Guthrie (pictured with her mother in May 2020) posted a video to her Instagram page on Wednesday addressing Nancy's alleged kidnappers
Savannah then directly addressed her mother.
'Mommy, if you are hearing this, you are a strong woman. You are God's precious daughter, Nancy,' she said.
Tucson television station KOLD News 13 received the first ransom note at approximately 5pm on Monday, February 2.
KOLD news anchor Mary Coleman appeared Wednesday on CNN and said the note contained 'information that only someone who is holding her for ransom would know'.
She also said the letter included a 'dollar amount' and a 'deadline'. That letter was sent to the Pima County Sheriff's Department.
TMZ appeared to receive this same letter on Tuesday and revealed that the alleged kidnappers wanted millions of dollars in bitcoin sent to a specific crypto wallet address. This address was verified as authentic by investigators.
The note TMZ received specified two deadlines. One was at 5pm on Thursday, which has already passed and another was on Monday, February 9.
The message warned that if the first deadline was missed, the demands would change and that there would be 'a more serious consequence' if the second deadline was missed, according to TMZ.
The KOLD news station received a second ransom note late on Friday morning. The Pima County Sheriff's Department said that the IP address from the email did not match the first one sent to the station earlier this week.
However, the station revealed that the sender used the same type of secure server to obscure their identity.
The station reported: 'The new note contains information the senders seem to think will prove to investigators they're the same people who sent the first note.'
On Thursday, Camron Guthrie confirmed that his mother's alleged kidnappers have not contacted him or anyone else in his family.
'We have to know that you have our mom,' Camron said in the family's latest video message. 'We want to talk to you.'
'We haven't heard anything directly,' he added.'We need you to reach out,and we need a way to communicate with you so we can move forward.'
On Friday, forensic FBI teams scoured the roof of her home and reportedly found a mounted camera that had been missed in previous searches.
As of Saturday morning, police have not identified a suspect or person of interest in the case. The only person who has been arrested in connection with the case is someone who allegedly sent fake ransom texts.
Investigators said Derrick Callella,a Los Angeles County man,sent a message on Wednesday to someone in the Guthrie family asking if the Bitcoin had been sent.