What are the five highest navigable lakes in the United States?

POST No. 1 - Here is the set up:
From the U.S. Army Corps of Engineers -
33 CFR Part 329 - Definition of Navigable waters of the U.S.
Section 329.4 - General definition
Navigable waters of the United States are those waters that are subject to the ebb and flow of the tide and/or are presently used, or have been used in the past, or may be susceptible for use to transport interstate or foreign commerce. A determination of navigability, once made, applies laterally over the entire surface of the waterbody, and is not extinguished by later actions or events which impede or destroy navigable capacity.
http://www.nap.usace.army.mil/Portals/39/docs/regulatory/regs/33cfr329.pdf

Great Lake Elevations (average elevation)
Superior - 600 feet
Michigan and Huron - 580 feet
Erie - 570 feet
Ontario- 245 feet

Not all that high, and not all in the U.S. Now See post no. 2...

POST No. 2 - please read post no. 1 first

Based on the definition from the previous post, and the Missouri and Columbia Rivers once being used for interstate and foreign trading, I give you The Highest Navigable Lakes in the U.S. (at least that I could find)

LAKE OAHE, the 4th-largest man-made reservoir in the United States, extends from Pierre, South Dakota to Bismarck, North Dakota. The lake is 231 miles long, has 2250 miles of shoreline, and has a maximum depth of 205 feet. (Missouri River) Average elevation: 1608 feet.
https://en.wikipedia.org/wiki/Lake_Oahe

LAKE SAKAKAWEA (Garrison Dam Reservoir) Missouri River, North Dakota elevation 1634 feet
http://www.mrd.usace.army.mil/rcc/plots/pixel/garr.gif

FORT PECK LAKE, Montana (Missouri River) 2222 feet
http://www.mrd.usace.army.mil/rcc/plots/pixel/ftpk.gif

CANYON FERRY LAKE, Montana (Missouri River) 3788 feet
http://www.mrd.usace.army.mil/rcc/plots/pixel/cafe.gif

FRANKLIN D. ROOSEVELT LAKE -1284 feet -formed by the Grand Coulee Dam on the Columbia River, in Washington state. The Columbia had been used by explorers and traders for the Hudson Bay Co. and the Northwest Trading Co. Therefore, by definition, it is a navigable lake.
http://www.nps.gov/laro/

Happy boating!