HENRYS FORK − NEAR ISLAND PARK DAM (ISLI1)
   State:  Idaho
   County:  Fremont
   Latitude:  44 24' 0" North
   Longitude:  111 22' 59" West
   Elevation:  6225 ft

   Supporting NWS Forecast Office: WFO Pocatello

   
Click for NWS Official River Forecasts for ISLI1
   

Daily Historical Statistics for May 26, 2026
Mean Stage: 3.82 ft  Mean Flow: 1030 cfs
Max Stage: 5.88 ft  Max Flow: 2530 cfs (1984)
Min Stage:  2.60 ft   Min Flow: 310 cfs (2003)

Statistics based on water years: 1933-2024
* statistics estimated based on current rating

The 4-10 Day Trend Forecast is based on model guidance and uncertainty during this period is greater.

Hydrograph plot for ISLI1

Data Used In Plot   "label   USBR Observations