13C−2H REDOR NMR experiments were performed on 30-residue (AlaGly)15 silk I mimics of Bombyx mori silk fibroin to gain structural details about the elusive structure of the silk I conformation. 13C,2H-labeling strategies are illustrated for measuring individual dihedral angles in peptides and for determining local structure by REDOR. A major turn of type II character is found in the region Gly(14)-Ala(17).