Sol 1809, Setpember 6, 2017, update by MSL scientist Roger Wiens: Curiosity is on the steepest part of Vera Rubin Ridge that it will encounter along its climb. The machine is performing superbly, having driven a 28 meter distance yestersol and having climbed 18 meters vertical elevation in four planning sols. The rover’s current elevation is -4202 meters.
Mars has far more extreme elevations than the continents on Earth, and it is reflected in the elevations of the landing sites to date. Curiosity landed at almost the same elevation as Viking 2 which landed in 1976 at -4.5 km. Curiosity may hopefully pass the elevation of Phoenix, which landed in 2008 at -4.14 km. The highest-elevation successful landing site to date was Opportunity, in Meridiani Planum, at -1.44 km. All elevations are measured relative to the mean planet radius… [More at link]