Detail of the somewhat confusing Rose Falls area. Many thanks to Clearwater Historic Lodge for providing this on their website, clearwaterhistoriclodge.com
Your trail (Caribou Rock Trail) runs north/south to the east of the creek. You can take the Border Route East from there.
A portage from Duncan Lake to Rose Lake (The Stairway Portage) runs twisting north/south to the west of the creek. You can catch the border route west from the stairway portage.
The only convenient connection between the two north/south routes is the small bridge that crosses the stream shortly before the falls.
Before heading west on the Border route to the Rose cliffs, head down 28 steps of the Stairway portage and check out lovely Rose Falls. When dome return up the 28 steps and take the signed Border Route trail west.