Here's why:
* California's climate: California generally has a Mediterranean climate with warm, dry summers and mild, wet winters. This is not conducive to the formation of glaciers, which require consistent cold temperatures and snowfall. While there are some higher elevations in the Sierra Nevada mountains that experience snow, it's not enough to sustain large, active glaciers like you find in Alaska or Greenland.
* Glacial features: Features like U-shaped valleys, cirques, moraines, and fjords are characteristic of glacial erosion. These features are not prominent in California's landscape.
So, while California has mountains, they formed due to tectonic activity (the movement of Earth's plates), not glacial erosion.
