This rapid is named after the limestone cliffs on river left along this rapid. Limestone rapid is fun at every level and can be run in a raft as low as 500 CFS. You can scout this rapid on river left.
Enter river right. There are a series of small waves leading to the largest drop in the rapid. Enter this drop with momentum and a river right angle. The Limestone hole/rocky ledge is on river left at the drop. Continue down river right shore to avoid two holes just left and right of center. Exit left to avoid the large rock pile along the river right shore.
The rapid classification jumps up to a Class IV+. A scout is recommended. You can run the same line as you do below 3,000 CFS just make sure you have strong paddlers and lots of momentum. The holes just left and right of center becomes very large at these levels, and the line to the right of them against the shoreline is much smaller. At extremely high flows a line along the river left shore opens up.
Limestone starts at 2:02. The water flow is ~2,400 CFS.
Limestone starts at 21 seconds. At this flow, around 3,800 CFS, you can see how large the holes are. This kayaker is able to cut left after the initial drop above the holes, which is a very difficult move to make in a raft and not the suggested raft line, but perfectly fine in a kayak.