I live about 5,300 feet in the high desert of Northern California. It can get up to 100 in Summer and can get below freezing in Winter. Sagebrush and juniper trees are the dominant plant life here. Will lavender grow well here?

Lavender should be able to well depending the type you go for. There are lavender grown in Sonoma County; I am unsure if you live further north than but lavender also thrives in Ontario which is a province known for hot summers and harsh winters.

I learned that there is 39 species of lavender maybe one of them would work for your location. I ask my nursery lots of questions. Maybe if you have a local one they could be a good source for you to chat with.