Climbability is here defined as the ability of a cliff face to be ascended from the ground up using traditional, non-invasive climbing techniques. A study was undertaken in order to assess the climbability of several sedimentary rock units and to develop a scale that quantifies climbability. A link was found between climbability and a unit's sedimentary characteristics. Twenty cliff sections in California, Arizona, Nevada, and Utah were analyzed and given a climbability (CB) score of 1-38 based on fracture length, fracture size, friction, friability, and cleanness. The Total CB score for each cliff was plotted against percentages of framework, matrix, cement, porosity, quartz, feldspar, lithologic fragments, sorting, roundness, and grain size. The most important factors in achieving a high CB score are high quartz content, a low percentage of rock fragments, and a high degree of sorting, with Pearson correlations of .849, -.822, and .802, respectively. Correlations between individual sedimentary characteristics and CB factors show a strong relationship linking these characteristics with favorable fracture size and length. Eolian dunes ean the highest CB scores, and the lowest scores are given to sedimentary rocks originally deposited in lacustrine/lagoonal or in alluvial fan environments.
