
Nan Aspinwall and her mare, Lady Ellen
Nan left San Francisco on September 1, 1910, riding her thoroughbred mare, Lady Ellen. She traveled light, not even taking extra food, water, or clothing, but only the bare essentials. She planned to stay in towns when she could and sleep out in the open if she had to. Extra clothing and supplies were shipped ahead to meet her along the way.
For the most part she followed the railroad tracks. She didn’t run into trouble until she got lost in eastern Nevada. She said she had taken a prospector’s trail as a shortcut. When it petered out, she tried to retrace her steps, but found that her horse’s hooves had left no mark on the rocky surface. She wandered for two or three days, with little food or water for herself or her horse, until she finally decided to let Lady Ellen find the way, and Lady Ellen led her to safety.

Salt Lake Tribune
According to the Salt Lake Tribune, reporting upon her arrival on October 31:
In zero weather with no shelter in the bleak mountains, no food for herself or her horse, she suddenly lost all sense of direction and for three days wandered helpless In the maze of the mountains. There were no trails, and she was forced to walk and lead her horse over mountain after mountain vainly searching for a trail. Finally she reached Proctor almost dead from exhaustion. Her shoes were worn from her feet and bleeding and fainting she stumbled into town.
Plucky hardly begins to describe her.
The story goes on to describe her appearance:
When she arrived in Salt Lake she declares she presented a sorry spectacle. However, her trunks had arrived, and Saturday night Miss Aspinwall went to church wearing a broad Stetson crown to her tawny locks, a silk negligee man’s shirt, a natty divided skirt and a pair of substantial riding boots. She was certainly a type of the charming, dashing poster cowgirl.
I am not sure what a “silk negligee man’s shirt” would look like — presumably it was made with a very lightweight fabric. She must have been quite the sensation in church.