California is weird. Some places are open and others are not regardless of what the official line is. You must either email or call and check. I’m guessing Alabama Hills is closed because I couldn’t get through by phone but they have an email form you can use.
Do not go by BLM postings because they are not always correct. You may be able to camp or boondock but not use facilities. Welcome to California, a giant cluster you know what.
I told someone about the Walmart near me. He called and the manager told him no. And now the place is filled with giant RVs not being hassled.
ALWAYS CHECK. Good luck to you!