This 1911 map confirms Sambo Slough entering Wakenda Creek/Canal opposite Camp Creek.

https://books.google.com/books?id=sWqwnrap5sAC&lpg=PA546&ots=fI6Rvw6iJ8&dq=map%20of%20sambo%20slough%20missouri&pg=PA546#v=onepage&q=map%20of%20sambo%20slough%20missouri&f=false

Further investigation reveals that the original course of Wakenda Creek is north of the current dredged canal which is really quite straight. Study of the above map shows the somewhat tortuous course just north of the canal. Study of the satellite view shows the original course of the creek north of the canal and south of CoRd 296.

Reviewing distances again shows what appears to be a field access road that may cross the old creek bed just north of ny previous located point. There is also a crossing of the old creek bed north of the bridge near the intersection of CoRd 420 and Creek 327. 2 miles from the mouth of Sambo Slough

If the viewer zooms out a bit, it appears that the afore mentioned field road continues across the creek and canal and skirts the east edge of the sambo slough area on the high ground. Or it might be my imagination....:>}