LINDSAY, OK - After seven days of searching the Marshall County sheriff's office says they've turned up no clues in the disappearance of Nathan Blankenship of Lindsay.
Sheriff Ed Kent says he suspects foul play may have been involved.
Investigators are also looking for Jessica Cornwell who may have been the last person to see Blankenship.
OSBI spokesperson Jessica Brown says a tip led agents to believe Blankenship left Oklahoma city the morning of February 2nd - headed for Marshall county.
According to Brown, "We often call on sheriff's offices as they do us when we need help. They have the man power to actually run more leads than we do."
Marshall county deputies say they have searched the area around Cumberland bottoms, where Blankenship was originally believed to be.
They are now expanding their search north.