What are the only two fresh water lakes completely within the United States that are larger than Lake Okeechobee. And where are they located?

One of the great lakes... lake Superior for sure, but I can't think of any others (maybe another one of the great lakes).

Lake Superior is shared with Canada. You might find your answer here:
Google Maps

Lake Okeechobee in southeastern Florida, U.S. is the third largest freshwater lake wholly within the country (after Lake Michigan and Iliamna Lake, Alaska).

Well, mcpowers, what was NOT pertinent in finding out the three largest lakes within the United States borders? You asked for the other two lakes larger than Lake Okeechobee and I found them - Lake Michigan and Iliamna Lake.