- Lake Almanor area, Plumas County, California53 objects
- Lake Annie, Modoc County, California1 objects
- Lakeside, South Lake Tahoe, El Dorado County1 objects
- Lassen County, California13,151 objects
- Last Chance Creek, Plumas County, California1 objects
- Lava fields, Siskiyou County, California1,301 objects
- Leavitt Station, Lassen County, California1 objects
- Likely Rancheria, Modoc County, California6 objects
- Likely, Modoc County, California5 objects
- Lincoln, Placer County, California2 objects
- Locality 2, Northeast Lower Klamath Lake, Siskiyou County2 objects
- Long Valley, Lassen County, California93 objects
- Loomis, Placer County, California11 objects
- Lower Klamath Lake Area, Siskiyou County, California1,291 objects
- Lower Klamath Lake, Siskiyou County, California1,280 objects
- Lower Scott River, Siskiyou County, California9 objects