Լարամիդյան օրոգենեզից անմիջապես հետո Ժայռոտ լեռները նման էին [[Տիբեթյան լեռնաշխարհ|Տիբեթ]]ին՝ ծովի մակարդակից 6000 մ բարձրությամբ։ Հետագա 60 միլիոն տարվա ընթացքում [[էրոզիա]]ն մերկացրել է բարձր ժայռերը՝ բացելով նրանց տակ գտվող հնագույն շերտերը։ Այսպիսով կազմավորվել են ներկայիս լեռները<ref name=gadd/>
The current southern Rockies were forced upwards through the layers of Pennsylvanian and [[Permian]] sedimentary remnants of the Ancestral Rocky Mountains.<ref>{{cite web|last=Lindsey|first=D.A.|year=2010|url=https://pubs.usgs.gov/circ/1349/pdf/C1349.pdf|title=The geologic story of Colorado's Sangre de Cristo Range|publisher=U.S. Geological Survey|id=Circular 1349|deadurl=no|archiveurl=https://web.archive.org/web/20170502034033/https://pubs.usgs.gov/circ/1349/pdf/C1349.pdf|archivedate=2017-05-02|df=}}</ref> Such sedimentary remnants were often tilted at steep angles along the flanks of the modern range; they are now visible in many places throughout the Rockies, and are shown along the [[Dakota Hogback]], an early Cretaceous sandstone formation running along the eastern flank of the modern Rockies.
Just after the Laramide orogeny, the Rockies were like [[Tibet]]: a high plateau, probably {{Convert|6000|m|ft|-3}} above sea level. In the last sixty million years, [[erosion]] stripped away the high rocks, revealing the ancestral rocks beneath, and forming the current landscape of the Rockies.<ref name=gadd/>
[[File:Jackson Glacier terminus.jpg|thumb|right|Glaciers, such as [[Jackson Glacier]] in [[Glacier National Park (U.S.)|Glacier National Park]], [[Montana]], as shown here, have dramatically shaped the Rocky Mountains.]]
