The highest point above the tunnel lies near the Tunnelspitz, at approximately 2,855 m (9,367 ft) above sea level (estimated from the Swisstopo topographic map [1]).
"Erfolgreiche Stromschienenversuche im Simplontunnel (Successful track trials in the Simplon tunnel)". Die Bundesbahn (in German) (3). Darmstadt: 268. 1989. ISSN0007-5876.