The Missouri Canoe & Floaters Association members rent canoes and display some of his maps on their website
OWWC members worked with the Ozark Society and others, including accompanying Supreme Court justice William O. Douglas on the river, to save what is now Arkansas's Buffalo National River.
Current and Jack's Fork National Scenic Rivers in Missouri are spring fed and have water in them most of the year.
American Whitewater gives water level info on some more technical streams.
OWWC member reports of stream conditions. (River Flow Rate Report Spreadsheet)