(CNN) -- More than a week ago, a 2-year-old girl with a wide grin and butterfly barrettes in her hair vanished in Mississippi.
Authorities hope she's still alive, and are offering a $20,000 reward for her return.
Myra Lewis was reported missing by her family on March 1 after playing with her sister outside their home in Camden, the FBI said.
She was last seen about 11 a.m. the same day wearing white or khaki pants, a turquoise sweater adorned with a bear, and pink tennis shoes. Myra is 37 inches tall and weighs 27 pounds.
"Since her disappearance was reported, multiple state, local, and federal law enforcement agencies have participated in a massive, collaborative search effort," the FBI Office in Jackson said.
"Significant resources have been dedicated to this investigation, including extensive ground and air searches, and utilization of specially trained search teams."
Despite the effort, the toddler remains missing, and the FBI is offering the money incentive for her return.
"We are confident that information will be uncovered which will lead to Myra's return, and we continue to solicit the public's assistance in locating this little girl," said Daniel McMullen, the FBI special agent in charge.
Madison County Sheriff Randy Tucker told CNN affiliate WAPT that he believes the little girl is in the area.
CNN's Suzanne Presto contributed to this report