Matthews 1026,
You should contact the rec area or Tahoe NF to confirm what is up with Stevens Trail, I am not familiar with it.
Be advised you should be prepared for all types of weather as at this time of year Any Type of weather can happen, the weather service is unreliable. The air will be moist due to being close to the river so the cold will leak right through your clothing as it absorbs more moisture and then of course your body is giving off moisture as well. Dress warm, have some sort of cover for the night, tarp or tent, and remember the water will be cold and it is running high. One little mistake on your part and you will be in the water and the cold will knock you out in ~ 15 minutes. Being swept into rocks at a fast rate of speed is No Fun and that alone can kill you. I've know of a fellow who went into the NFAR for opening day of trout season, they found his body towards the end of summer way down river and it was not pretty!
It should be beautiful out there but be careful!.................63bkpkr