There are several types, some are hardier than others. I think that Mahonia aquilfolia is native to the US but wether it is hardy all over I could not say.

My mahonia came with the name Oregon Grape. None of it was edible, and I understand there are many, many types. Just not for us up here in The Land of Ice and Snow.

I googled it and this is what came up.

(Mahonia trifoliolata, Agrito, Laredo Mahonia and Mexican Barberry, has a subtle tart red berry eaten raw or used in jellies, preserves, sauces, drinks, cakes and tarts. Mahonia bealei, the Leatherleaf Mahonia and Beal's Barberry, has berries edible raw or made into various thinks like pies, jelly and wine.

The berries are edible, and rich in vitamin C, though with a very sharp flavor. Although edible, the plants contain berberine, a compound found in many Berberis and Mahonia species, which can cause vomiting, lowered blood pressure, reduced heart rate, lethargy, and other ill effects when consumed in large quantities.)

I can say though that the birds love both the flowers and the berries.

A related species, Mahonia aquifolium ("Oregon Grape" ) was eaten by settlers in North America and was formerly a food crop of native peoples.

@Fernapple Great information,. Thanks, Fernapple.