That's one odd mountain!
05AB1E, 54 52 47 46 bytes

ÅÉ¹L£D€g__ÏRv"/ \ "yg×N·©úˆyvy4yg-ð×}J®&gt;úˆ}¯R»


Try it online!

Explanation

                                                # implicit input n
ÅÉ                                              # push a list of uneven numbers up to input
  ¹L£                                           # divide into sublists of length 1,2,3...n
     D€g__Ï                                     # remove empty sublists
           R                                    # reverse list
            v                                   # for each sublist
             "/ \ "                             # push the string "/ \ "
                   yg×                          # repeat it len(sublist) times
                      N·©ú                      # prepend (sublist index)*2 spaces
                          ˆ                     # add to global list
                           yv                   # for each number in sublist
                             y4yg-ð×            # prepend spaces until length is 4
                                    }           # end inner loop
                                     J          # join to string
                                      ®&gt;ú       # prepend (sublist index)*2+1 spaces
                                         ˆ      # add to global list
                                          }     # end outer loop
                                           ¯    # push global list
                                            R   # reverse it
                                             »  # join rows by space and columns by newline
                                                # implicitly print


I could have saved 5 bytes with ÅÉ¹L£D€g__ÏRv"/ \ "yg×N·©úˆy4jJðÛ®&gt;úˆ}¯R» if only I'd pushed that bugfix for j I wrote several weeks ago :/