The private plane was mostly quiet. There was a nervous energy for the three Oklahoma football coaches onboard. They’d never done what they were about to do.It was Sunday, Dec. 1, 2002, the first day coaches were allowed to visit high school juniors for recruitment. A day earlier, these coaches had been on the sideline as Oklahoma lost to in-state rival Oklahoma State, effectively dashing their hopes of appearing in the BCS national title game. But on this one-hour flight, they had other concerns. As the plane neared Texarkana, an appropriately named border town sandwiched between Texas and Arkansas, they talked about the fact that none had never been to a prison before for a recruiting visit. “All I could relate it to was what I saw on TV and in the movies,” said Cale Gundy, Oklahoma’s running backs coach at the time. “We just didn’t know what it would be like.” They also talked about the player who had them flying to visit a federal prison. He was good enough, they thought, to change an already successful program. But he would require a recruitment unlike any they’d ever experienced. Still, Adrian Peterson was worth it. Thus, the coaches headed to the federal prison where Adrian’s dad, Nelson, was incarcerated. Said Gundy: “We knew it was going to be a battle all the way for him.”Jeff Harrell came to Palestine High as the defensive coordinator and head track coach when Peterson was a sophomore. Peterson wasn’t on the varsity football team that year because he was academically ineligible. So Harrell didn’t work with Peterson until the track season that spring. Peterson’s mom, Bonita, was a former track star; his dad was a former college basketball player. After the school’s first track workout, Harrell decided to have Peterson run on the team’s 4×100-meter relay team in addition to the 100- and 200-meter individual events. But Harrell encountered a problem. Harrell taught relay runners to stand 15 steps behind their starting mark to allow time to gather the baton from the previous runner while getting up to top speed. But when Peterson started running, the sprinters behind him with the baton couldn’t catch him. So Harrell had Peterson move up to 10 steps behind the starting mark. Then five. “That didn’t work,” Harrell said. So Peterson was told to stand at the starting mark until he received the baton. Harrell feared a collision. But each time, Peterson grabbed the baton and sprinted away so fast that, somehow, it worked. “I remember going home every day and telling my wife, ‘I’ve got this kid and I’ve never seen anything like him in my life,’” Harrell said. Peterson ran a 10.6-second 100-meter dash that year. He set a personal best of 10.26 seconds two years later, a time so fast that if it weren’t for football, Harrell believes Peterson could’ve become an Olympic sprinter. Peterson played on both sides of the ball as a sophomore on the JV team, playing running back and outside linebacker, but as a junior on the varsity team, Harrell, by then the head coach, put an end to that. Harrell didn’t want to be the coach who got the country’s best football recruit hurt while playing out of position as a linebacker. Peterson ran for 5,011 yards in his two varsity seasons. He averaged 11.7 yards per carry as a senior. He had 32 touchdowns. And he rarely played after halftime because his team was so dominant. When Peterson’s high school career finally came to an end during a playoff loss his senior year, Harrell was filled with relief more than disappointment. “I just thought: Thank God I got through this and he didn’t get hurt,” Harrell said.In East Texas, Petersons’ exploits were well known. Some members of opposing teams hung around the field after games in full uniform, sharpies in hand, waiting for Peterson to emerge from the locker room so they could get an autograph. But Harrell didn’t get a full grasp of Peterson’s celebrity until a trip together to Ohio after the season, where Peterson was going to be named the national offensive player of the year. As they waited together in the security line at the Dallas-Fort Worth airport, a TSA agent called them over. “Before he shows an ID or anything, the man says, ‘Oh, you’re Adrian Peterson,’” Harrell said. “That was one of the first times it hit me that, ‘Oh man, everybody knows this kid.’”At the Federal Correctional Institution Texarkana, guards asked the visiting Oklahoma coaches for their IDs and had them walk through a metal detector. They then guided the coaches to a picnic table in a vast courtyard. A water tower in the distance was the only obstruction against the vast East Texas sky. Nelson came out and was joined by Bonita, Adrian and one of Adrian’s younger brothers. They talked about academics at Oklahoma (Nelson at one point had been committed to play basketball there) and the football program. Aside from the location, it was a normal recruiting visit. “We sat out at that picnic table in the facility for a couple of hours,” Bob Stoops said. “They were fantastic to be with and visit with.” Adrian told a few schools how important it was to ensure his dad, who was incarcerated when Adrian was 13 after being convicted on federal charges of laundering money acquired from the distribution of crack cocaine, was involved in the recruiting process. “We had gone through all kinds of red tape for a couple months leading up to being allowed to get in and visit with them,” Stoops said. “So after that, other people tried. But because of all the logistics those people had to coordinate, (the other recruiters) said to heck with this, we’re not doing this anymore.” USC had tried unsuccessfully to meet with Nelson. And while Peterson liked coach Pete Carroll and assistant coach Ed Orgeron, he wanted his dad to be able to watch his college games, which would’ve been tough if he chose USC. So Orgeron got resourceful. “I tried to get the guy transferred to (a prison in) Los Angeles,” Orgeron said on “The Dan Patrick Show” last year. “Yeah, I tried. Couldn’t get it done, but I competed.”Since Peterson didn’t play as a high school sophomore, some schools wanted to see him in person before believing the hype. When a Texas A&M assistant was led into the school and introduced to Peterson — 6-foot-1 and 210 pounds — wearing a sleeveless shirt and seemingly having muscles atop his muscles, Harrell said the coach uttered: “God almighty.” Texas A&M offered Peterson a scholarship the next day. Harrell advised Peterson to be polite and accommodating to every college coach who walked through the door. One day, the Oklahoma coaches visited the high school and had trouble locating Peterson. Eventually, he was found in an empty classroom with coaches from Texas A&M-Kingsville, a Division II school. “He was being as nice as he could be, doing exactly what I told him,” Harrell said with a laugh.In the spring of 2003, Peterson visited Oklahoma for the first time. The Sooners…