Welcome aboard. You do realize that this is an open carry forum, right?
As for your question, you could go look at their doors,
or you could check www.friendorfoe.us
And probably someone in ND will be along shortly.
IIRC, Marcus is not anti-rights.
Here's a thread of stores in WI which are posted, starting with a list of corporations. Marcus is not among them, & it's a WI company.
Whatever you do, do NOT call & ask.
You'll likely get some low-level minumum-wage person who doesn't know corporate policy but does have an opinion & isn't hesitant about expressing it.