small mouth on this one for her size Bill. probably not any more gape than the 5 pounder i just removed and posted about recently. that one was 4". i am quite sure this one was 4" as well, give or take a fraction. but this is an atypical fish. real small head/large body. the 5 that i culled was just the opposite - big head/small body. if i can catch her again, i'll try get you an exact gape measure. sorry for forgetting. that's just not something i'm used to doing.