lowest signed summit

[Jim]

Here's the westbound.



And here's a bit of a view of what Oacoma looks like from I-90 as it climbs west from the Missouri River.

[empirestate]

In Massachusetts, there is a sign for the highest elevation on the Mass Pike, at 1724 feet. It's not as low as the others mentioned, but it's still relatively low, especially since it covers I-90 in several states.

Well, there's added significance in that it's signed as the highest point on 90 east of the Rockies.  This always felt counterintuitive to me, but the Appalachians turn far east starting in Pennsylvania, and west of the Hudson 90 follows the low "water level" route across NY, so it makes sense.

At the risk of nitpicking..  Oacoma, South Dakota, where the I-90 climbs above its max elevation in the Berkshires, is very far to the east of the Rockies.

I am probably being loose with the details, and it sounds about right that South Dakota is the next highest point west.  I'm sure someone has a picture of the sign.

Interestingly, the higher elevation in South Dakota is achieved more through the gradual sloping of the continent from east to west than from any localized ascent. I remember the first time I saw Oacoma, SD and thinking what a letdown it was from my years of seeing the Mass Pike sign.

[Jim]

Interestingly, the higher elevation in South Dakota is achieved more through the gradual sloping of the continent from east to west than from any localized ascent. I remember the first time I saw Oacoma, SD and thinking what a letdown it was from my years of seeing the Mass Pike sign.

Yes, the area as I remember it has grassy, rolling hills but definitely nothing approaching a mountain until you get to the Black Hills well to the west.