are there any walmarts open 24 hours?

The Modesto Walmart on McHenry is open 24hrs.

Modesto has one

Yes

I think the store on McHenry closes at midnight or so and opens about 6:00 am

Modesto

Galt as well. And the store on McHenry Ave. in Modesto.

In the local area, Sonora, Lodi and Los Banos are the only ones left.