Ever wonder where that place name came from? I found a scanned copy of a 1916 journal article “California Place Names of Indian Origin” on the UC Berkeley Library website. Check out this entry for Azusa:
Ha! I like footnote #6, and I paraphrase: some guy living in Azusa quotes some other guy who’s godfather said it means “skunk hill” because of the skunks, the small polecat variety, on the hill named “Azuncsabit” by the Indians, east of the town where the ranch house of the grant stood.
And here I thought Azusa got it’s name from the phrase “the best city from A to Z in the USA!”
You can download the PDF of the journal article here.
I also bought this book many years ago and it’s pretty interesting if you are into the etymology of place names:
SoCalGIS.org 
How cool is that? I wonder if anyone has mapped those place names. I shall have to buy that book and spent far too longer reading it than I have time for!