She is believed to be with 20-year-old Jacob Jennings.
Officials said King had been making phone calls to her friends, but now her phone is no longer in service, and her family is concerned for her welfare.
King is 5'2'', 128 pounds.
She has brown hair and brown eyes.
She was last seen wearing a black shirt and black pants.
If you know where Sierra King is, please call Wichita Falls Police at 761-7792.
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