score:2
With some detective work, it's possible to work it out.
Firstly, Frommer's now states that there's a visitor center at the Scorpion Ranch, so we can be pretty sure it exists.
On Yelp - there's a photo of the Visitor's Center.
So now we know that exists, and what it looks like. Another photo here
Then - is there a ranger...well...it's stated that if camping, you need to present your reservation to the ranger, and that a ranger is present on every island.
The visitor center itself doesn't look like it's liveable - it's more of an exhibition center for visitors to view. There's a gallery inside available.
So presumably there's an abode elsewhere for the ranger.