Cisco’s Sonar

By Bryce Nielson, The Cisco Kid

WHY THE LAKE WON’T FREEZE AND WHERE ARE THE CISCO?

Bear Lake is always full of surprises.  Just when you think you have figured it out, it changes.  Folks that have lived here for over 30 years have always expected the lake to freeze four out of five years.  In those days, we suffered through winds and temperatures down to -20F all winter long.  In the past few years, things have changed. The frequency of the Lake freezing has declined, obviously because of weather and lake elevation fluctuations.  Visualize Bear Lake as container of water in a freezer.  At a constant temperature, the container with less water will freeze quicker.    As the temperature of the freezer climbs, the slower the water freezes.

There are two types of water that comes into the Lake.  The consistent flow from tributaries and springs that come in at an average of 45F.  When the Bear River is diverted into the Lake through Mud Lake the temperature of the inflow water is considerably higher.  This water comes in and floats on the cold water in the Lake.  Add the increased heating from the warm summers and in the end, it all mixes together to make the entire Lake warmer.  For the Lake to freeze, the outside air temperature needs be cold for a long period of time.  The weather has been moderate in December and January, and we will have more cold temperatures in the future but not enough to freeze the Lake.  We have also not seen the valley full of fog which precedes freezing.

PacifiCorp is keeping the elevation of the Lake higher than normal for future changes in operation. 

In fact, I don’t recall the Lake being this high in January in the past 40+ years.  This along with the warmer water temperatures have impacted the spawning time for cisco.  Presently there is twice the normal spawning area due to lake elevations.  Spawning fish are not limited to Cisco Beach but can also use other rocky substrates (marinas and shorelines). Fishermen have been successful jigging them off the Rockpile albeit later than normal. Fishermen did start netting cisco off the State Marina Sunday morning.  There is no reason to worry about the cisco population being low.  DWR monitors the population every summer and there are still millions of them.  The Bonneville cisco are spawning but you just can’t see them.