Hunt on for missing Texas father-of-two who disappeared on his 5am morning walk as police reveal they have found his discarded coffee tumbler on the trail

• e-mail

The search for a Texas man who mysteriously disappeared on an early morning walk over the weekend is still on, leaving his wife and two young kids with more questions than answers.

Colby Richards, 31, was last seen by his wife, Callie Richards, 34, who awoke early Friday to find her six-foot-three spouse strangely missing from her bedside.

The pair live in a heavily wooded community north of Houston known as The Woodlands, and Richards atypically left through the home's back gate for what his wife hopes was his usual 5am workout.

Causing further concern, she told reporters Monday, is the fact the gate was inexplicably left ajar - leading cops to speculate the dad wandered into 28,000 tree-filled acres behind the house. They have since recovered a Yeti coffee tumbler belonging to the beloved dad, but have gleaned few leads aside from that.

Residents and law officials are now canvasing the woods in search Richards, an engineer, part-time baseball coach, and father to a three-year-old daughter and one-year-old son.

Scroll down for video: 

The search for Colby Richards, a Texas man who mysteriously disappeared on an early morning walk on Friday morning, is still on - leaving his wife and kids hoping for his safe return

Richards, a 31-year-old, six-foot three engineer, was last seen by his wife, Callie Richards, 34, who awoke early Friday to find her spouse strangely missing from their bed

'It is very bizarre. It feels like there’s just so many things – so many possibilities – it’s really hard not to wonder all of the things that could have happened,' Richards told Fox 26 reporters outside her Musgrave Place home on what was Day 4 of the search. 

'Normally, in the morning he leaves around 6:30 for work,' the mom, visibly emotional, said of the strange disappearance. 'He got up at some point and I could just feel that he wasn’t there. I go downstairs – he’s not down there. He’s nowhere.'

Callie Richards added that her husband typically wakes up for work around that time, at around 5 or 6 a.m., but that morning, she did not hear him getting ready.

When she went outside to investigate, she noticed the back gate to her home was left open - an unusual occurrence for two reasons, according Callie.

The first, she said, was the fact that Richards usually leaves for his morning routine through the front - and while hiking and meditating in quiet areas is not atypical for the missing father, it's not part of his usual pre-work routine.

The second, she told the station with tears in her eyes, is simply the detail that the dad would have usually been sure to lock the gate to the family home when leaving - raising, in her mind, a red flag.

'I go outside – I can see that the back gate is open,' she said Monday. 'He never goes out the back gate. That’s not something typical. 

'Right away, I just knew something wasn’t right. I called 911.'

The pair live in a heavily wooded community north of Houston known as The Woodlands, and Richards atypically left through the home's back gate for what his wife hopes was his usual 5am workout

Causing further concern, Callie told reporters Monday, is the fact the gate was inexplicably left ajar - leading cops to now say the dad wandered into around 28,000 tree-filled acres, with his whereabouts now unknown

In the days since, Callie has been joined by countless locals and law officials for daily searches of the surrounding woods, trails, and roads near the property - but have so far failed to turn up anything immediately useful

Searchers are seen canvasing the woods near the couple's home, which stretches for several thousand square acres

Seen here are some of the search patterns enacted over the past five days in the search for Richards

In the days since, Callie has been joined by more than 50 locals and volunteers for daily searches of the surrounding woods, trails, and roads near the property.

They spent their Memorial Day - and the preceding weekend - canvasing different areas, an effort that continued Wednesday as Montgomery County detectives revealed they found a coffee tumbler belonging to Richards lying upright at an unspecified trail entrance.

The item was found on Friday, and is so far the only lead made public in what is being treated as a missing persons case.

'No diagnosed mental health issues, no previous disappearing – he’s never left like this before,' Callie said Monday, pleading for her husband's safe return.

 'This is not something that’s normal for him.'

Speaking to The Sun, Richards' cousin Allison Fox revealed she was told by Callie that nothing noteworthy happened in the days leading up to her husband's disappearance, as she continues to look for answers. 

'She's just as surprised as the rest of us,' Fox said Tuesday - Day 5 of the ongoing search effort. 'He just kind of walked out and didn't say anything.'

Callie, meanwhile, confided to Fox 26 how Richards' disappearance was already affecting the pair's young children, the eldest of whom is already aware of the situation.

'My daughter knows,' Callie conceded Monday of her eldest daughter now being aware of the situation. 'Initially, we tried to keep it quiet until we could get more information, but she knows. She’s been asking questions, like morbid questions... She’s very aware of what’s going on'. She added of her one-year-old (not pictured): 'My son has been leeching to me'

Richards is described as being 6’3,195 lbs. with an athletic build, as well as blue eyes and dark blonde hair

Those with information regarding Richards' disappearance are urged to contact the Montgomery County Sheriff's Office, which is treating the case as that of a missing person

The search for Richards is still ongoing, with the scrutinized area measuring in at more than 26 square miles

'My daughter knows,' she conceded Monday. 'Initially, we tried to keep it quiet until we could get more information, but she knows. She’s been asking questions, like morbid questions. She’s very smart. She’s very aware of what’s going on.'

She added of her one-year-old: 'My son has been leeching to me.'

Jake Stovall, the leader of a nonprofit contributing to the search, said volunteers will continue searching in the coming days, through the night with thermal imaging tools if necessary. 

'It’s search and rescue, it’s not recovery,' the Gulf Search and Rescue director said, hopeful the father is alive and just yet to be found.

'We fully believe that he’s still alive, he’s still out there, and he just needs help coming home,' Stovall said. 

He remarked of the bizarre details surrounding the man's  disappearance: In 19 years, I've never seen a case like this. 'A 31-year-old male who’s in good health.'

Callie, in a tearful message to her husband, added Monday; if you are out there and see all of this stuff going on, and you feel scared in any way - please come home. It doesn't matter - once you walk through the door, everything will be all right.'

The search for Richards, meanwhile, is still ongoing, with the scrutinized area measuring in at more than 26 square miles. DailyMail.com has reached out to the Montgomery Country Sheriff's Department for an update on the case.