USGS gauge at Goldbar. (also available through the NOAA hotline 206-526-8530). Although you can certainly paddle this section much higher than 4000 cfs, it starts to become a bit less suitable as a beginner training ground. The rapids don't become significantly more hazardous as levels rise, but the current is faster and rescues can become more challenging. Those with a strong roll and good boat control skills shouldn't have much problem up to 10,000 cfs at which point features start to wash out.