For anyone else interested, I took this route today. Easily passable. Very fun drive. My only complaint is the amount of trash on the beach in Sea Rim State Park. It was disgusting and I've never seen anything like it.
SOLD!
For sale is a set of N-Fab Rails. These have detachable steps. They were on our 2018 4Runner less than 3k miles. New condition. No scratches or dings. All mounting hardware is included.
$300 obo. Pickup in Kingwood, TX.
https://n-fab.com/rkr-step-system/2018/toyota/4runner