untamed

adj

1. Wild, uncontrolled, especially of animals not domesticated or trained to human contact.

   “The mustang is an untamed horse that roams where it wants, with little interest in humans.”

   “Kjelsås (six miles) marks the end of the suburbs, and the line immediately plunges into Nordmarka. This vast untamed area of forest and mountain (much of it over 2,000 ft. above sea level), interspersed with innumerable lakes, large and small, is known as Oslo's playground.”

   “John Wesley Powell ... the one-armed Civil War veteran led nine men in four wooden dories down the untamed and uncharted Colorado River and into the equally untamed and uncharted Grand Canyon.”