The last mile or so of the Snoqualmie Valley Trail is closed to bicycles and pedestrians very close to Rattlesnake Lake. The trail is being used for vehicle access to residences on Edgewick Rd while Edgewick is being repaired. Edgewick is not a detour option. The SVT should reopen in early April according to King County.
Detour options are not good. The route beginning with 136th Ave SE at I-5 is strongly discouraged due to extreme grades, poor sightlines, and fast drivers. A safer option is to follow permanent 4078 Snakebit backwards from North Bend. This is a substantially more difficult route than the SVT’s nice railroad grade. The best option is probably to choose other routes while the SVT is closed.
Note that permanents continuing up the Palouse to Cascades Trail (Iron Horse) past Rattlesnake Lake are deactivated due to the serious washout that occurred in December. The rideability of most of those routes is moot anyway while the Snoqualmie Tunnel is closed for winter.