US-20 West at US-18/US-85 in Lusk. Use US-18 East/US-85 North to Newcastle. Use US-20 West/US-18-West/US-85 South to Douglas (via US-18/US-20) and Torrington (via US-85).
US-18/US-20 East/US-85 North at US-20
US-18/US-20 East/US-85 North at US-20 East in Lusk. Continue on US-85 North/US-18 East for Newcastle; turn right for US-20 east to Chadron (Nebraska).