Different sections have very different elevation profiles. The Erie Canal section is mostly flat because it mostly follows the canal and rivers.
The Champlain Valley section is more hilly because it mostly uses roads.
And the Hudson Valley section has more elevation changes than you might expect, but they are mostly gradual - it follows old rail lines more than the Hudson River.
Note that all three charts start at Green River, where the three trail sections converge.
Green River is actually a few miles north of Albany, but we refer to Albany as the starting point
because it's a more familar reference point for most people.
Near Clyde, Erie Canalway