Here is the elevation profile for the 150. Approximately 7600 feet of climbing by Ride with GPS. It rides like more. This is the route that is most subject to change at this point, but you get the idea. It’s not flat.
You can switch to either distance at mile 84; from the 150 to the 200, or you can drop from the 200 to the 150 if it’s not your day. You’ll need to let the checkpoint volunteer know, and carry both sets of cue sheets because copies will not be available.