Jeanne Carr, a botanist and educator, became an important mentor and friend to Muir. She encouraged his writing and helped him connect with other influential people.

Muir married Louie Wanda Strentzel, daughter of a prominent Polish horticulturist, Dr. John Strentzel. The marriage provided Muir with financial stability and allowed him to pursue his writing and conservation work.

The Muirs' first daughter, Wanda Muir, was born.

The Muirs' second daughter, Helen Muir, was born.

Muir lived with his family on the Strentzel fruit ranch in Martinez, California. He managed the ranch's operations for several years, while continuing his writing and conservation work.

Louie Strentzel Muir passed away, leaving John Muir a widower. This was a significant loss for Muir, who had relied on her support and companionship.