After 1900 Christopher turned to hosting County Fairs and Sunday School Conventions and focused on improving Pertle Springs. In 1902 Christopher funded the construction of a new depot at the Dummy terminal, a new boat house, and a merry-go-round. The hotel also received some upgrades. In 1903 the large tabernacle that Sam Jones used for his gatherings was torn down and replaced with a new structure, which came to be referred to as the "Convention Hall."In December of 1905 Christopher remodeled the Hotel Estes in downtown Warrensburg and the dummy line that conveniently ran in front of the hotel quickly facilitated guest travel to and from the hotel to Pertle Springs.
Postcards featuring Pertle Springs from the early 1900s to the 1920s era are the most prevalent and featured the Estes Hotel, Minnewawa Hotel, the spring, the dummy line, and various recreational activities that visitors to the springs participated in while visiting.
By 1916 visitors increasingly drove their automobiles to Pertle Springs. One visitor who came in 1916 was a farmer from Grandview, Missouri, Harry Truman. He drove his 1911 Stafford automobile that he purchased in 1914 to the Springs for a visit. The rise of the automobile changed the landscape for Pertle Springs and made traveling by train to Warrensburg less important and also eliminated the need for the dummy line to take people to and from the Holden street depot to the resort.
In 1921 Pertle Springs suffered severe storm damage and a dam, which was constructed near the Stewart Cottage, partially washed away and eroded the bedding under the track for the dummy line and damaged the dummy line depot platform. It is unclear whether or not the storm damage factored into the decision to discontinue the use of the dummy line, but in March of 1922 Christopher made a decision to sell the dummy line and equipment.