s spin is locked to its momentum. Recent years have seen a dramatic surge in the studies of spin helical edge modes, with a particular emphasis on coupling with s -wave superconductors to engineer Majorana fermions [00,00] . The accessibility to Majorana modes, combined with their potential as the building blocks for fault-tolerant quantum computation [00,00] , has made the host materials of helical conductors desired systems for future quantum devices. Of particular interest are quantum Hall based systems that provide a robust platform for spin helical edge conduction [00-00] . Our proposed valley helical edge modes in the quantum Hall regime (Fig. 0 ) extend beyond such helical channels of the spin variety. Although it remains to be seen whether the valley, often considered as a pseudospin [0-0,0-00] , can lead to similar Majorana physics as the spin degree of freedom, our results certainly enrich the potential of multivalley systems for device application. We acknowledge support through the National Science Foundation (Grants No. ECCS 0000000 and No. DMR 0000000) for measurements. For sample fabrication and characterization, we also acknowledge the National Science Foundation (Grant No. MRSEC DMR 0000000), the Gordon and Betty Moore Foundation (Grant No. GBMF0000), and the Department of Energy Basic Energy Sciences (DEFG00-00-ER00000). [0] 0 O. Gunawan , Y. P. Shkolnikov , K. Vakili , T. Gokmen , E. P. De Poortere , and M. Shayegan , Phys. Rev. Lett. 00 , 000000 ( 0000 ). PRLTAO 0000-0000 00.0000/PhysRevLett.00.000000 [0] 0 O. Gunawan , B. Habib , E. P. De Poortere , and M. Shayegan , Phys. Rev. B 00 , 000000 ( 0000 ). PRBMDO 0000-0000 00.0000/PhysRevB.00.000000 [0] 0 M. Shayegan , E. P. De Poortere , O. Gunawan , Y. P. Shkolnikov , E. Tutuc , and K. Vakili , Phys. Status Solidi (b) 000 , 0000 ( 0000 ). PSSBBD 0000-0000 00.0000/pssb.000000000 [0] 0 A. Rycerz , I. Tworzydlo , and C. W. Beenakker , Nat. Phys. 0 , 000 ( 0000 ). NPAHAX 0000-0000 00.0000/nphys000 [0] 0 J. R. Schaibley , H. Yu , G. Clark , P. Rivera , J. S. Ross , K. L. Seyler , W. Yao , and X. Xu , Nat. Rev. Mater. 0 , 00000 ( 0000 ). NRMADL 0000-0000 00.0000/natrevmats.0000.00 [0] 0 H. Zeng , J. Dai , W. Yao , D. Xiao , and X. Cui , Nat. Nanotechnol. 0 , 000 ( 0000 ). NNAABX 0000-0000 00.0000/nnano.0000.00 [0] 0 A. M. Jones , H. Yu , N. J. Ghimire , S. Wu , G. Aivazian , J. S. Ross , B. Zhao , J. Yan , D. G. Mandrus , D. Xiao , W. Yao , and X. Xu , Nat. Nanotechnol. 0 , 000 ( 0000 ). NNAABX 0000-0000 00.0000/nnano.0000.000 [0] 0 Y. P. Shkolnikov , K. Vakili , E. P. De Poortere , and M. Shayegan , Phys. Rev. Lett. 00 , 000000 ( 0000 ). PRLTAO 0000-0000 00.0000/PhysRevLett.00.000000 [0] 0 Y. P. Shkolnikov , S. Misra , N. C. Bishop , E. P. De Poortere , and M. Shayegan , Phys. Rev. Lett. 00 , 000000 ( 0000 ). PRLTAO 0000-0000 00.0000/PhysRevLett.00.000000 [00] 00 O. Gunawan , T. Gokmen , K. Vakili , M. Padmanabhan , E. P. De Poortere , and M. Shayegan , Nat. Phys. 0 , 000 ( 0000 ). NPAHAX 0000-0000 00.0000/nphys000 [00] 00 T. Gokmen , M. Padmanabhan , O. Gunawan , Y. P. Shkolnikov , K. Vakili , E. P. DePoortere , and M. Shayegan , Phys. Rev. B 00 , 000000 ( 0000 ). PRBMDO 0000-0000 00.0000/PhysRevB.00.000000 [00] 00 M. Rasolt , in Solids State Physics , edited by H. Ehrenreich and D. Turnbull ( Academic , San Diego, 0000 ), Vol. 00 , p. 00 . [00] 00 M. Rasolt , B. I. Halperin , and D. Vanderbilt , Phys. Rev. Lett. 00 , 000 ( 0000 ). PRLTAO 0000-0000 00.0000/PhysRevLett.00.000 [00] 00 A. F. Young , C. R. Dean , L. Wang , H. Ren , P. Cadden-Zimansky , K. Watanabe , T. Taniguchi , J. Hone , K. L. Shepard , and P. Kim , Nat. Phys. 0 , 000 ( 0000 ). NPAHAX 0000-0000 00.0000/nphys0000 [00] 00 B. E. Feldman , M. T. Randeria0 , A. Gyenis , F. Wu , H. Ji , R. J. Cava , A. H. MacDonald , and A. Yazdani , Science 000 , 000 ( 0000 ). SCIEAS 0000-0000 00.0000/science.aag0000 [00] 00 Z. Zhu , J. Wang , H. Zuo , B. Fauqu