Malum Prohibitum is correct, there is no duty in GA to disclose voluntarily. The next question one might ask is whether or not one should disclose in the absence of a requirement to do so. There are varying opinions on this topic. Reasons for disclosing usually given are to earn good will with a LEO who may be waffling on whether to ticket you are not, and to avoid an escalation if you are searched for some reason. Reasons against disclosing are that not all LEOs are CCW-friendly, you are inviting the LEO to disarm you and "inspect" your weapon, and GA's firearms laws are so flaky that it's difficult to know in any given spot in the world whether it is legal to be packing, even with a GFL, so you might be confessing to a crime.