Carrizo Plain, California

Bounded on the east by the Temblor Range and on the west by the Caliente Range, it extends for 50 miles. (Wiki article)

Yes, those are swaths of purple flowers in the middle ground.

Entire hillsides!!!

Dispersed camping is allowed on the perimeters in the foothills and mountains, but I saw no enforcement people. But then I was on the east side where there are VERY few people.