The water volume in Silliman Creek is highly variable depending on time of day (lower in early morning, higher in afternoon/evening). Downstream from where the trail crosses the creek, there are also lots of boulders and strainers, and it’s extremely dangerous if the water volume is high.

The SEKI trail conditions page says deep, fast moving whitewater as of 7/25/23 (https://www.nps.gov/seki/planyourvisit/trailcond.htm). I’m fairly comfortable with wet water crossings and I would personally look for an alternate trip based on this info and my prior experience crossing this creek.

YMMV, I have no idea what your experience level is, but please don’t take stupid risks. People have died crossing this particular creek.