This morning Jim Walmsley destroyed the FKT for both the Rim to Rim and R2R2R at the Grand Canyon. That's correct, took down the one way record as the start to his out and back attempt.
Took 5 mins off the R2R record and 25 off the out and back.
http://trailrunnermag.com/people/news/2311-jim-walmsley-destroys-grand-canyon-double-crossing-record