[2] During the American Civil War, President Abraham Lincoln appointed Everts as assessor of Internal Revenue for the Montana Territory, a position he held between July 15, 1864 and February 16, 1870.

[2] In 1870, Everts, a former assessor for the territory of Montana, joined an expedition led by Henry D. Washburn and Nathaniel P. Langford into the wilderness that would later become Yellowstone National Park.

The next year, Everts' personal account of the experience, "Thirty-Seven Days of Peril", was published in Scribner’s Monthly.

[2] In spite of their assistance, Everts denied Baronett and Pritchett payment of the reward, claiming he could have made it out of the mountains on his own.

[9] After the two expeditions and the fame from his article, Everts was offered the position of first superintendent of the newly established Yellowstone National Park, but he declined since it did not include a salary.