Subdomain displaying 404 errors

I have several sub-domains on a WP multisite. One of these sites recently began returning 404 errors on every page except the home page. I tried…

(1) Disabling all plugins.
(2) Resetting permalinks.
(3) Verifying the .htaccess file was correct.

Unfortunately, I can’t seem to find the problem.

I know this isn’t much information, but hoping someone can offer suggestions as to what might be causing the issue with this particular sub-domain when the others are functioning normally.

http://riverlodgeandgrill.com/

Thanks.