Officials with BC Parks are assessing the damage and it's not known when the popular hiking and biking trail will reopen.
Myra Canyon Trestle Restoration Society director Ken Campbell describes the slide as catastrophic.
He says the springtime freeze-thaw cycle pried several boulders from the rock face above one trestle, and the resulting slide was very destructive.
All other trestles and pathways along the trail are also being inspected for any damage.
The century-old Kettle Valley Railway, including more than a dozen soaring rail trestles through the Myra Canyon, has been dramatically upgraded over the last decade since a wildfire destroyed 12 of the historic wooden spans and damaged two steel trestles. (CKFR)