A mother from Wise County has been missing for more than two weeks, and her family is pleading for help as the search intensifies.

Darla Hastings, the missing woman's sister, says the pain of not knowing is unbearable.

"Every day I cry myself to sleep. I cry myself awake, and it's another day that no one's heard anything," Hastings said.

Sister vanished after camping trip

Every day of Hastings' life is filled with heartbreak and agony since her sister, 48-year-old Monica Sanford, went missing.

"Her and the ex-boyfriend left to go fishing and camping, and only the ex-boyfriend returned," Hastings said. "Monica always said if anything happened to her, to look at her ex-boyfriend."

The mother of five was last seen at a property along Cuba Road in Bridgeport on Aug. 23. Sanford's family reported her missing two days later.

Missed birthday raises concern

"Her daughter turned 28, and Monica did not reach out at all. That is not Monica," Hastings said. "She has five kids. Her daughter is pregnant and is expecting in December."

Investigators found Sanford's vehicle abandoned in a field not far from the property where she was last seen. Since then, they've searched the area with sonar and drone technology, as well as K-9s.

Investigators suspect foul play

"We have several people that we're currently talking to, and they're being cooperative," Hastings said.

Wise County Sheriff's Office Chief Deputy Eric Debus believes foul play is involved.

"We don't believe she left on her own accord," Hastings said. "She left behind personal belongings that most people would not leave without, including a small dog that she was very fond of."

Family pleads for public's help

Hastings is begging anyone who may have information to come forward.

"Please help me find my sister. If nothing else, we need closure. She deserves to be found. She doesn't deserve wherever she is right now," Hastings said.

Sanford's disappearance adds another layer of tragedy for the grieving family.

"Our mother actually passed away a year ago in February. A drunk driver killed her," Hastings said.

Reward offered for information

Texas EquuSearch is offering a $5,000 reward for information leading to Monica's whereabouts. Anyone with information is asked to call Texas EquuSearch at 281-309-9500 or the Wise County Sheriff's Office at 940-627-5971.