"The principal or highest part of the mountain having changed its direction to east and west, I ascended it in such manner as to leave its most elevated ranges to the south and travelled north west over a very rough and broken country generally covered with snow"

In the quote from William Henry Ashley, a 19th-century American explorer and fur trader, he strongly explains his journey through a mountainous region. Ashley's account reflects both the physical obstacles and the navigational choices he dealt with throughout his exploration.

"The principal or greatest part of the mountain having altered its direction to east and west", shows that the mountain range he was navigating through all of a sudden moved its orientation. Originally anticipating or accustomed to a different directional alignment, this change seems significant enough for Ashley to mention. Mountain ranges generally possess complex topographies, and a shift in their direction could substantially impact the tourist's path, affecting his bearings and subsequent decisions.

"I ascended it in such way regarding leave its most raised varieties to the south" recommends that Ashley selected a path that circumvented the greater peaks. By opting to leave the most raised parts to the south, he likely prevented the arduous task of climbing the steepest areas, maybe to conserve energy or time, or due to the restrictions imposed by the weather and surface conditions. This choice highlights the strategic thinking needed in exploration, stabilizing the demands of the landscape with the abilities of the expedition group.

"Travelled north west over a very rough and broken nation normally covered with snow", paints an image of the difficulties Ashley dealt with. The "very rough and broken nation" conveys the uneven, potentially treacherous surface, which would have needed substantial effort and caution to traverse. The reference of snow shows extreme climate condition, including another layer of problem to the journey. Snow-covered landscapes can obscure trails, hide possible risks, and make complex development, demanding extra navigation abilities and durability.

In general, Ashley's description reflects the intricacies and difficulties of early 19th-century exploration, needing flexibility and careful decision-making while browsing unknown and frequently inhospitable landscapes.