Immigration Law Questions? Ask an Immigration Lawyer.
People who ask a question like this on this site -- and you wouldn't believe how many people do every day -- are usually involved with an online romance who has convinced them that they are an heiress. Frequently, they also claim that the inheritance is contingent on her finding the right man. And then, suddenly, though you've never met her in your life and have no idea if she is real or not, tag, you're it. You're told that you're the right man and that it's your job to clear her inheritance so that she can send it to the States and you and she can live happily and wealthily ever after.
All of this is nonsense. Ghana is a very poor third world country, but the country does have gold mines and the government strictly controls when gold can leave Ghana. One must make arrangements with the government to send gold abroad. It all must go through Ghana's PMMC, a government agency that regulates gold exports.
You should get yourself a lawyer in Ghana to do this right. However, don't get one through your so-called girlfriend. Scammers work in teams and they play parts in each other's scams to bolster each other's lies. Call the US Embassy in Accra and ask them for some names of reputable lawyers who can assist you to bring gold over. That way, you won't be fooled.