Bear Lake Fact Sheet

Bear Lake has 4 endemics species of fish

Q: Can you name them?

• Bear Lake Whitefish
• Bear Lake Sculpin
• Bonneville Whitefish
• Bonneville Cisco

Q: What is endemic anyway?

A: Endemic means fish only live in Bear lake. They are not found anywhere else in the world! Why in Bear Lake? Geographic isolation – for over 10,000 years these endemics have evolved to match the Bear Lake’s unique water chemistry, structure, climate and physical forces.

FYI: Cisco spawn during the month of January in rocky-bottomed portions of the lake. Rock is often associated with the shallow margins of Bear Lake. Cisco spawning offers a unique angling experience; the fish are scooped out of the water through large holes in the ice by dip nets, when ice is not on the lake boats and waders allow access. Anglers consume some cisco but more use the fish as bait for trout.

The lake has 48 miles of shoreline. In contrast to the shallow beaches, the average overall depth of the lake is 94 feet. It drops down more than 200 feet in its deepest spot. When the lake is full, its surface covers 109 square miles. It is more than 20 miles long and about eight miles wide.

Bear Lake is approximately 8 miles wide and 20 miles long.

Q: Is it true that they’ve never found the bottom?

A: No, not true, but for a long time no one could determine the depth with the usual rope & weight method. This may have been because the bottom in the deepest parts of the lake is the settling place for “marl”, a very soft form of calcium carbonate that forms a thick but soft bottom, making it difficult to “feel” the weight bottom out.

The USGS sonar studies in 2003 produced a bathymetric map of the lake showing the deepest part of the lake to be 208 feet when the lake is full. The deepest part is on the east side in Utah just off South Eden.

View the USGS Geophysical Survey of Bear Lake

Bear Lake sits at an elevation of 5,924 feet.

Q: How old would you say Bear Lake is? How long has the Lake been around?

1. Just over 100 years. Built by Utah Power & Light
2. 10,000 to 15,00 years old – the result of glaciers melting in the valley
3. More than 250,000 years old – the result of tectonic activity

The correct answer is 3 – More than 250,000 years old!

The USGS core samples that have been scientifically dated indicate that Bear Lake is more than 250,000 years old!(There are older, deeper cores that have not yet been studied!) Giving Bear Lake the title of the “oldest continually wet lake in North America”!

The actual formation of the lake was by faulting (tectonic activity / earthquakes) where the mountains on both the east and west sides of the lake rose and in between subsided. The lake, as we know it, has been isolated from the river for the last 10,000 to 15,000 years. There have been other forms, both shallower and deeper, depending on freezing and melting of glaciers during the ice ages, effecting of how much water came into the valley and tectonic activity that blocked the river flows causing it to back up and overflow the lake basin making it 60-80 feet deeper!

Note* The Power Company didn’t build the lake but did turn the lake into a reservoir by diverting Bear River into the lake to store water, creating a series of canals to move water around and building the Lifton pumping station to pump water back out of the lake.

Q: Will Bear Lake always be blue?

A: We don’t know! The fact that man now diverts the Bear River into Bear Lake for irrigation and power generation may have detrimental influence the beauty of the lake.

It’s important to have more knowledge and understanding of Bear Lake through good science and monitoring. Bear Lake Watch has been instrumental in bringing partners together to fund a major monitoring project on the lake conducted by USGS. The primary objective is to quantify current water quality and weather conditions and build a robust baseline data set that can be used to assess future water quality changes.

Visit USGS.gov to read more about Bear Lake’s water quality

If you’ve been to the shoreline of Bear Lake, you’ve probably noticed the small shells – maybe just a couple scattered about but often in great piles.

Q: Where are the creatures that made them?

Q: What are they?

Q: Do they outgrow their shell, drop it and grow another one?

A: The creatures that formed these shells have been long-gone for nearly 10,000 years! The shells have lasted this long because of the calcium chemistry in Bear Lake water. Some that do get crushed become part of our sand.

According to a U.S. Geological Survey study, the shells were in great abundance in the shallows of Bear Lake when the lake was around 50 feet higher and filled the whole valley. These shells are well preserved and have been dated to be 10,000 years old (Smart, 1963). Curators at the Smithsonian Institute identified all 6 species of snail and one species of clam.

Read about Paleo-biology and paleo-hydrology of the Bear Lake Basin, Utah

Q: Is it true that Bear Lake water turns some of the fish blue?

A: No, not exactly, but…

The locals call the Bonneville Cutthroat Trout “blue noses” because when they’re caught in the lake they have a very blue tint. Additionally, the cute little Bear Lake Sculpin has Bear Lake blue eyes!

It is important that we do what we can to help safeguard these unique species.

Read more about the Bear Lake Sculpin

USGS fact sheet about the Bonneville cutthroat trout

Q: How much did Bear Lake go down when Lake Bonneville blew out?

A: Trick question! Although two lakes existed during the same time span, they were not connected, so the Bonneville break-out at Red Rocks Pass would not have directly affected Bear Lake.

Bear Lake is at 5,924 feet MSL and the highest Lake Bonneville ever got was approximately 5,100 feet. The remnant of Lake Bonneville is the Great Salt Lake which is roughly 4,200 feet MSL (historic average from Wikipedia).

(Think about when you drive down to the Salt Lake valley note where you see the old Bonneville shoreline that is mined extensively for gravel and treasured for the Bench neighborhoods.)

FYI: It is that drop in elevation that was so enticing for the industrialists of the early 1900s. Every foot of drop equates to generation of additional electrical power. The key was to control it; for that they desired to harness Bear Lake.

Very ingenious for the times, but no one considered what would happen to Bear Lake.

Sometimes Bear Lake seems full and sometimes very low.

Q: Who decides what the water level will be?

A: The power company, PacifiCorp /Rocky Mountain Energy

They obtained the permissions to use the top 21.65 feet Bear Lake in 1907, a time when there was little concern for the natural resources, therefor few constraints on operations.

They determine a lake storage plan based on a number of factors:

• Current level
• Projected inflow
• Flood liability situations

The out flow is determined legally by:

• Operations agreements with the Bear River Compact States (ID, UT,WY)
• Delivery contracts water with several irrigation companies downstream.
• And the Bear Lake Settlement Agreement which was signed by Bear Lake interests (Bear Lake Watch) the Bear River Water Users Association (the irrigation interests) and PacifiCorp. Among other things, it provides that less water will be used as the lake get lower.

So, no, Garden City does not have influence to keep it low so the beaches and business are better.

The use as supplemental irrigation exaggerates a normal wet-dry cycle of lake levels. During wet years the Lake stays relatively high, but in prolonged droughts, the lake level can drop 3-5 feet a year exposing large areas of lakebed.

Bear Lake can appear as sheet of glass – like a mirror, so reflective you can see every detail of the clouds and mountainside on the far side of the lake, but it can change in minutes forming huge waves.

Q: How do the waves get so big so fast and how large can they get?

A: Size and type of wind-generated waves are controlled by:

• Wind velocity, Wind duration, Fetch, and Original state of the surface
• As wind velocity increases wave length and height increase.
• The resulting wave size depend on the wind duration and fetch.

Q: At Bear Lake, we all get wind velocity and duration, but what’s fetch?

A: Fetch is the uninterrupted distance over which the wind blows without changing direction. So, our East or West winds have the shorter distance -8 miles across, but the North or South have more than double – 20 miles of lake plus the open flat land on either end!

BTW: Waves are an important to the form and function of Bear Lake. They created the original shape and help keep the shoreline functions when at natural levels. The can miss-shape the lake and cause havoc and mayhem when the water’s edge is unnaturally move about.

Read more about wave measurement

Q: Which way does the water flow in Bear Lake?

A: Sometimes the water appears to be flowing in one direction and a little later in a different direction!

What looks like water flow is usually wind chop or wave action, so which ever way the wind is blowing creates the appearance of flow.

Though not highly visible, Bear Lake does have natural currents that are caused from the spinning of the earth, the winds and are influenced from the natural tributaries.

What is very visible is the inflow from the man-made diversion of the Bear River. In high water years this can come with great force and carry a heavy load of sediment and nutrient. It comes in from the north, pushing southward but can be seen going along the east shoreline and almost always along the west shoreline. Just to confuse matters more, when the pumps are turned on the water mass is sucked back to the north!

It is important that we understand the natural currents and the effects of man’s manipulations. Some information will be come from the platforms studies on going on the lake.

Ice! Ice Baby, Ice! You might need some today for this heat. It’s hard to imagine Bear Lake freezing over.

Q: Does it ever freeze completely over? How often?

A: Bear Lake has frozen 68% of the time in the last 97 years. However, it has only frozen over 44% of the time in the last 25 years (1995-2019).

The last time it was completely frozen was January thru March of 2016, for 84 consecutive days.

There were several times it didn’t freeze over for 3 consecutive years, but this last winter was the first time it didn’t freeze over for 4 consecutive years.

Q: How much electrical power is generated at the Lifton Station?

A: None! Lifton Station has 5 pumps that use electricity to pump water out of Bear Lake.

Q: Who is Responsible to see to the protection and preservation of Bear Lake?

People Own it, States Hold it, Power Corp Operates it, Irrigators Use it, Feds Inhibit it, Agencies Permit it, Businesses Sell it.

Our goal and mission at Bear Lake Watch is to keep this lake we love clean, deep and blue.

Get involved and make a difference today!