Within two years, Helen was again healthy and the Lincoln's started to work with the Desert Mission, the haven for the sick and poor of Sunnyslope. He promoted Phoenix as a haven for health seekers. In 1933, the Lincolns’ made an initial donation of $2,000 which helped buy 20 acres for the Mission's expansion. This initial donation was the first of many contributions which he made to the organization which was renamed the John C. Lincoln Health Network in 1954. Helen fought and worked for the burgeoning network. Lincoln became the director of the Desert Mission of the Young Men's Christian Association and the Good Samaritan Hospital in Arizona. In 1936, there were approximately 600 residents in Sunny Slope. There was still much vacant land, covered with vegetation and cacti. As the Sunnyslope neighborhood grew, the medical functions of the Desert Mission became a separate entity by the 1950s, later known as the John C. Lincoln Health Network, and now known as "HonorHealth" after a 2013 merger with Scottsdale Healthcare. The Desert Mission remains in operation as a subsidiary of this healthcare group. Lincoln also joined in the construction of the Camelback Inn in Scottsdale, Arizona. Lincoln had made many investments in real estate and owned large tracts of land between the slopes of Mummy and Camelback Mountains. The property was a remote desert scrub land located outside Phoenix and had no water, electricity or telephone access. Jack Stewart, a sportswriter and publicist, approached Lincoln with an idea. He wanted to build a pueblo-style hotel which could reflect Southwestern and Native American culture rather than the more commonplace dude ranch-style resort. Lincoln became convinced that the project had potential and invested $200,000 plus, the land that he owned between the Mummy and Camelback Mountains. The Camelback Inn opened on December 15, 1936, under the management of Stewart, with the slogan "Where Time Stands Still". There were accommodations for 77 guests. Lincoln served as president of the Inn from 1936 to 1959. The resort became very popular among Hollywood celebrities and political leaders. Among the early celebrities who frequented the Inn were Mrs. Dwight D. Eisenhower, Clark Gable, Jimmy Stewart, Bette Davis, and J.W. Marriott, Sr., who shared the Stewart's love for the Camelback Inn. In 1968, the Camelback Inn was purchased by Bill Marriott of Marriott International and in March 2003, the hotel was officially renamed by its parent corporation as "Camelback Inn, a JW Marriott Resort & Spa".