You would canoe the Dismal River over a two-day period for a total of 24 miles. The river is swift, tight, and challenging for most. You must be in control of you canoe at all times, no coasting. You have to duck under barbed wire, downed trees, and maneuver around stumps and rocks constantly. The river runs around 5-8 mph. It has several attractions worth stopping for. One in particular is a 125-foot deep sinkhole made from a natural spring. Another is a 3-foot "Waterfall" over which you can canoe with some difficulties. There are several beautiful stops along the way to soak up the sun, eat, and to play in the river. It averages about 2 feet deep with others much deeper. It is best to make arrangements with private landowners to camp on their land.
Mitch Glidden of Glidden Canoe Rentals usually charges $44/day per canoe and maybe $3-5/day camping fees.
From Omaha, you would take I-80 to Grand Island exit. Take Highway 2 all the way into Mullen, Nebraska. See Mitch.
Mitch Glidden will take you to the put-in point just off of US Highway 83. From there you are on your own. You usually take out at "Senaca Bridge", or you can attempt (NOT) to canoe all the way down to Highway ...