Totally agree the way of determining navigability and use for commerce is vague and probably intentionally so at the time it was passed, though why I can only speculate.
I used to post frequently to this site but moved to WI a few years back. I still take interest in Missouri fishing as I get to fish here every once and a while when visiting family. Have spent lots of time fishing the upper Meramec for smallies and trout and on the Current.
I like Wisconsin's model for gaining public access to private stream reaches:
!) Pay the owners to lease the strips of land buffering the water.
2) Use influence of groups like TU (with a formidable presence in the state) and the DNR resources to find willing landowners and make it happen. Apply for state and federal grants to improve water resources on large tracts of stream thru habitat improvements, etc.
3) Use funds from inland trout stamp purchases (where all money goes to improving stream habitat or acquiring landowner easements).
Wisconsin State Statue 29.191(4)(e) states: “The Department shall expend the receipts from the sale under this subsection of inland waters trout
stamps on improving and maintaining trout habitat in inland trout waters, conducting trout surveys in inland trout waters and administering
this subsection.”
Missouri has on books in Objective 3.2 of the 2003 trout plan to consider purchasing easements. Has this taken shape?
I propose a trout habitat improvement stamp be offered to help raise revenue for habitat restoration projects and land access. The MO trout plan is clear that if there is interest in this sort of thing the MDC will work as a partner, but I don't think they will go in alone (at least during tough financial times).
Regarding WI water access laws:
All stream water is PUBLIC. Landowners do not own the stream bed but own the land immediately adjacent. Access laws are such that if you access a creek (no matter how small) from a public area (bridge, natural area, park, etc), you are legal to fish as long as you keep your feet wet (stay in stream). Can get out of stream if the stream is impassable (which is subject to interpretation I imagine). Cannot access streams from private property without permission.