https://sbcovid19.com/vaccine/
You'll scroll down to Appointments, then select San Bernardino County public health sites. That's where you'll find locations giving vaccines.
Just a thought...
Most people who want to get vaccinated are probably going to start at the top of the page.
As you go down the page, there are other providers, and when you get to the bottom, you find grocery stores and pharmacies. A lot of people will pick from the links at the top, and not the ones at the bottom.
We had no trouble getting an appointment at RiteAid in Phelan for my wife.
As usual, your mileage may vary. The state wants to take over the whole system, so if you're qualified and in a hurry, take the time to study the whole county vaccine page.