Lake Monsters: Here’s Why Sturgeon Grow to Be So Big in Shasta Lake

For anyone who’s been lucky enough to take a trip to Shasta Lake, you’ve surely heard of the legend of giant sturgeon sitting on the bottom of the lake. I have to admit, the legends even freaked me out as a kid. With modern-day photos and videos, we’ve actually seen some of these fish reach up to 500 pounds. So why the heck do they get so big? That’s actually a story that’s 75 years in the making.

Sturgeon are an ancient species of fish that have been known to grow to 12 feet long at up to 3,000 pounds (the record sturgeon weighed in at 3,463 pounds. These distinct look fish live most of their lives feeding at the bottom river deltas near the ocean, like the Sacramento River delta, and swim upstream to spawn. Their life cycle is typically 50-60 years, but they can grow as old as 100 years.

To get a quick glimpse of what a giant sturgeon in Shasta Lake looks like, here’s a video of a fisherman catching one in the summer of 2020:

So how the heck do these fish grow to be so big in Shasta Lake? When the Shasta Dam was constructed in 1945, the sturgeon who traveled to the Upper Sacramento River to spawn were stuck, unable to return to the Delta they typically inhabit. With a completely altered environment, these sturgeon rose to the top of the food chain, hunting for small prey at depths of 400-500 feet at the bottom of Shasta Lake. There, they could grow to enormous sizes.

A female sturgeon typically spawns at around 15-20 years, meaning these fish could be nearing 100 years old after getting stuck in the newly formed lake in 1945. At the end of their life, after feeding on larger prey in the deeper Shasta Lake for 75 years, these fish can grow BIG.

Over the past five years, people have either caught these fish or found them dead on the shores of the lake. These sturgeon have either died from old age, or in one case, got caught choking on food. Since they are so difficult for fishermen to catch, you have a better chance of finding one dead than catching one.

Although seeing one of these massive fish is rare, just know that they are certainly swimming under you in Shasta Lake. No need to worry They may be massive and may look mean, but they’re no danger to humans.