As of now, there are two Santa Teresa Boulevards in the South Bay - one from Route 87 south towards the north side of Morgan Hill, and one on the west side of Gilroy.
With the similar names, I had wondered if the two were meant to connect. Turns out that this has been planned since...1969!
http://www.morgan-hill.ca.gov/index.aspx?NID=880
As the project most directly affects the existing Hale Avenue section, that name has been applied to it (I don't know if Santa Teresa will be used as the name of the entire street once this is completed).
Looks like there's still a gap to the south?
The only gap is in Morgan Hill.
I'm pretty sure it was meant to connect, but developments in the West Dunne area probably impeded that in the 70s. Morgan Hill is pretty good about filling gaps in. Butterfield Blvd has been disjointed for a while, but now it runs complete from Cochrane Rd. to Tennant Station Rd.
Honestly, the gap isn't that big. It's just a 1/2 mile stretch between Main Street and Dunne. (Sunnyside Ave could be Santa Teresa Blvd.)
Some of the right of way connecting Hale and DeWitt is visible in Google Maps' property line delineation:
https://maps.google.com/maps?q=Morgan+Hill&hl=en&ll=37.121779,-121.659958&spn=0.010933,0.017724&sll=39.395877,-77.002487&sspn=0.339068,0.567169&hnear=Morgan+Hill,+Santa+Clara,+California&t=m&z=16
Interesting. I also note that there is a short gap in Santa Theresa before it reconnects to US 101 on the south end of Gilroy. Fill that one in and the corridor will continue into and well beyond Hollister.
What's the prognosis on that one (assuming that California's budget mess can be cleared out of the way)?
Mike