The Western Garden Book has a section on natives.
A fast growing native check out Flannel Bush - fremontodendron california. With pruning you could keep it to 4 feet but it might be wider than you want.
I think a couple of native ceanothus would do also.
Check into your city laws also. They probably have other junk around you can't see and that causes rodent problems.

Katita, you have several choices that would work for a hedge/screen. "Gardening with CA native plants" by Bornstein and Fross is a good resource.

Since you are interested in native plants/gardens, you might want to sign up for the Going Native Garden Tour on April 20

Here's a few natives that make good screens:
Ceanothus ("Ray Hartman" in particular is fast growing, but rather tall-15-20')
Toyon (Heteromeles arbutifolia)
Myrica californica
Manzanita ('Howard McMinn' is pretty good)
Lemonade Berry (Rhus integrifolia)

You also might want to check out the Las Pilitas web site.

wanda

Here is a link that might be useful: garden tour

The suggestions offered, all good, are also pretty large for a city lot front yard. Dendromecon harfardii or California bush poppy grows to about 4 to 6 feet high and about as wide. It is evergreen with flushes of yellow flowers throughout the year. Al

Wanda's suggestions are all good.

We actually grew ceanothus "Ray Hartman" along a wall and it grew from a 5-gallon can to 10ft. high in about two years. It's not too hard to keep it vertical so it doesn't take up so much horizontal space--I think we pruned it hard once a year right after blooming.

Also, lavatera assurgentiflora makes a gorgeous, super-fast growing, evergreen, everblooming, hummingbird-magnet, no-water screen. The downside is it requires very hard pruning a couple of times a year but can totally take it.

Fuchsia flowered Gooseberry (Ribes speciosum) makes a nice small hedge about 4 or five feet high. It is evergreen if it gets a little summer water, and has a great display of flowers that hummingbirds love in spring. It is thorny, so isn't for every location.

I saw some Fremontia yesterday. It was enormous! It's beautiful but I think too big for a garden, There are some smaller selections like Ken Taylor.

The Lavatera is wonderful and so is Ceanothus 'Concha'

Dendromecon would make an especially lovely hedge. It's thick enough that it would block the sight of those junkers.

sounds as if the planting space is narrower than desired "hedge" height. that's very limiting. :-(
myrica has unpredictable reputation (i've never done anything with it).
the rhus is very tough, but wide (my limited experience). lavatera is fast but a wide blob, and becomes old fast. (i guess you could replant).
a. 'Howard McMinn'... hmm, googling shows it gets taller than i thought i'd ever seen it. i wonder if it opens up below like most (all?) the taller arctostaph?
prunus ilicifolia is good, but gets rather large.

i'd start toyon for a few years with some irrigation. they'll be decent size but some will have dropped out or develop stubborn openings. so you could fill with e.g., a more upright variety of ceanothus. and shove a few more species in there. a uniform hedge looks dorky. :-)

Prunus illicitifolia makes a very attractive, dense hedge and is extremely tolerant of pruning. Can be held at any height from four to ten feet tall.

Ryan

These are all great suggestions. Do keep in mind that "California natives" are not all one and the same, and sometimes, non-native plants may be more eco-friendly to your area compared to natives from parts of California with a different climate. Redwoods, yuccas, and oaks all come from different types of habitats, as do the plants around them.

I have a beautiful ceanothus hedge in my yard. Right now it's in full beautiful lilac blue bloom. It shapes into a hedge very nicely. Dendromecon is a rangy bush and doesn't form a hedge. I have a flannel bush as well and it's pruned into a nice box hedge. But it grows very quickly and has to be pruned back every summer. It's also in full bloom and is covered in waxy yellow flowers. Maybe even Toyon can be hard pruned to a hedge. Or even a california laurel. I never tried though I have both plants. Both have to be pruned because they are very fast growers in Southern Cal. Manzanita makes a good bush, but I've never made it into a hedge. You really want to see those striking red trunks and limbs. Maybe even try California bush poppy: Carpinteria. It has lovely white poppy-like blooms each spring. It is a very compact grower. At least for me.