I can't speak for all locations in Oklahoma, but it is not invasive in dry shade (where it only gets rainfall and never is irrigated) in our woodland in southcentral OK. We only have a few and they are widely scattered over many acres of woodland. I think if you planted it in an area where you irrigate or if you gets tons of rainfall most years, it likely could become invasive. By contrast, coral berry, aka as Indian currant, grows in the same locations in our woodland as pigeonberry and is very invasive. We lost a lot of the pigeonberry in the drought of 2011 but didn't lose the coral berry, so I took that to be a sign that pigeonberry isn't as drought-tolerant, and that may be why it doesn't spread thickly or widely in our woodland.