The Moffat Tunnel route had a maximum grade of 2%. The west side of the Tennessee Pass route has grades up to 3%. However, the east side of the Tennessee Pass has a maximum grade of only 1.4%. The Denver & Rio Grande's acquisition by Southern Pacific (SP) in 1988 made Tennessee Pass once again the preferred transcontinental route. SP had a central route from California through to Kansas via Donner Pass, Tennessee Pass and trackage rights on the former Missouri Pacific route from Pueblo, Colorado into Kansas. The Moffat Tunnel route was kept in use. In 1996, UP bought Southern Pacific. UP preferred the Moffat Tunnel for routing traffic. The last revenue train went over the Tennessee Pass on August 23, 1997. Soon after UP ran this last train, they applied to the Surface Transportation Board for permission to abandon the line. Currently, the line is not of much use as the former Missouri Pacific line to Pueblo has been partially abandoned so trains would have to travel from Denver south to Pueblo before heading west. The of the Tennessee Pass line through the Royal Gorge is currently operated by the Royal Gorge Route Railroad, who operates excursion trains out of Cañon City. On July 10, 2012, part of the old tunnel collapsed, creating a sinkhole that damaged U.S. Highway 24 and forced its temporary closure between Redcliff and Leadville. The newer tunnel was not damaged. A report released by the Colorado Department of Transportation on September 4, 2014 stated the following about the line: Union Pacific began actively discussing the sale of the line to Colorado Pacific in 2019, for an amount of $10 million. However, Colorado Pacific wanted to pay only the $8.8 million that the line was valued at. After a long battle in court, the ICC declared that they would not force a sale, but if other evidence was found, Colorado Pacific could re-file the report. , Colorado Pacific attempted another forced sale, this time saying they’ll run passenger/excursion service over the route. Union Pacific responded by stating they were in active negotiations for Rio Grande Pacific to operate the line and were opposed to Colorado Pacific's bid. On December 31, 2020 Rio Grande Pacific subsidiary Colorado, Midland & Pacific Railway Company, announced it had entered in an agreement with Union Pacific to explore reopening, leasing and operating the line for both potential commuter and