South Dakota State and Nebraska-Omaha will see more than enough of each other on the wrestling mat this season.     The North Central Conference rivals hook up for the first time this weekend as both teams take part in the Harold Nichols Open on Saturday in Fort Dodge, Iowa.     South Dakota State is ranked No. 2 in Division II while UNO is fourth. Iowa State, ranked sixth in Division I, is expected to bring their entire team to the meet.     Heavyweight Jon Madsen heads the list of returning wrestlers for South Dakota State. Madsen won the national title in 2000 before finishing second last season.     The Jackrabbits also return third-place finishers Aaron Veskrna (149 pounds) and Todd Paszek (184), and fourth-place finisher Tyler Bryant (165).     South Dakota State also returns two-time All-American Tyler Jones, who redshirted last season. Jones is expected to be at 184.     Madsen, Bryant and Veskrna, who is moving up to 157, are each ranked second. Jones is ranked fourth.     "It's a pretty normal year with Nebraska-Omaha, North Dakota State and us battling it out again," SDSU Coach Jason Liles said.     Nebraska-Omaha returns three All-Americans - juniors Zach Stalder (174), Chad Wallace (197) and Roderick Ratcliff (141) - from the team that tied for third in the nation last season.     Wallace is ranked No. 1, Stalder is No. 3 at 184 and Ratcliff No. 5 at 141.     Top-ranked North Dakota State, the defending Division II champion, will compete for the first time as it plays host to the Bison Open in Fargo, N.D. Among the teams competing is defending Division I champion Minnesota, which returns eight All-Americans.     North Dakota State returns national champions Todd Fuller (174) and Nick Severson (heavyweight) along with All-Americans Lucas Christianson (sixth at 133), Brian Kraemer (sixth at 197) and Grady Wolf (eighth at 165).     The Bison are seeking their third straight national championship and fourth in the past five years under legendary coach Bucky Maughan, who enters his 38th season in Fargo.     "I think we are going to have a good team again," said Maughan, whose team also won a national title in 1988. "It should be a very close battle. We return seven starters and we hope to be among the top three or four teams battling there at the end. We have been able to peak at the right time the last few years."     Third-ranked Central Oklahoma is slated to compete at the Central Missouri Open on Sunday.     Central Oklahoma also will be strong again. The Bronchos are led by returning national champion Cole Province, who won the 133 title last March as a freshman. Teammate Muhammed Lawal also returns after finishing second at 184.     Central Oklahoma's Mark Dodgen, a national champion in 2000, returns after finishing third at 125 last season. Dodgen was upset in the first round of last years NCAA meet before taking the long road through the consolation bracket.     Province is ranked No. 1 while Lawal, who is moving up to 197, and Dodgen both start the season No. 2.