Construction of the remaining line proceeded rapidly to Daggett, California, where it connected to the Atchison, Topeka and Santa Fe Railway (ATSF), and the complete Salt Lake–Los Angeles line was opened on May 1, 1905. In California, Clark negotiated a trackage rights agreement from Daggett to Riverside, California, allowing his new line to use the existing ATSF route over Cajon Pass, in lieu of constructing its own tracks across the pass.
Construction of the final leg of the railway was completed quickly, reaching Daggett, California, where it linked up with the Atchison, Topeka and Santa Fe Railway (ATSF). The entire Salt Lake–Los Angeles line opened on May 1, 1905. In California, Clark secured a trackage rights agreement from Daggett to Riverside, allowing his new line to utilize the ATSF's existing route across Cajon Pass instead of building its own tracks through the pass.