I found this on the COE site. It's the bottom elevations for all the ramps.

Boat Launching Ramps
Bottom of Ramp Elevation (feet)
Bryant
207.0
Choctaw
191.0
Grenada Landing
191.0
Hugh White State Park
193.0
Gums Crossing
206.0
North Abutment
207.0
North Graysport
207.0
Piney Woods
204.0
Skuna-Turkey
205.0
South Outlet
156.0
South Outlet Old River Run
159.0
South Graysport
191.0
Torrance Landing
191.0
Upper Yalobusha
211.5
Wolf Creek
191.0
Young’s Landing
191.0