Snagging is only legal during an open snagging season in a designated snagging area.
From the 2015 Kansas Fish Regulations Summary. Find the complete Regulations Summary at: http://kdwpt.state.ks.us/content/dow...tions%2015.pdf
Snagging: Except for paddlefish and nonsport fish, which may be snagged in designated waters during designated seasons (See Page 7), fish may be hooked only in the mouth to be considered legally caught by hook and line. If hooked elsewhere, the fish shall be returned immediately, unrestrained, to the water. Nonsport fish (See definition Page 8) may be taken by gig, crossbow, and bow and arrow. Blue, channel and flathead catfish may be taken by bow and arrow where no length limits on catfish are in effect.