Wade decided in July he'd like to extend a two-year offer to the coaching staff and approached owner Drayton McLane and president of baseball operations Tal Smith about the idea.
"I just think the way that they've come together as a unit and the way they've worked with Millsie and the way they've been able to carry the message and the plan out on the field and communicate it with the players has put us in a position where I really think we have a strong, stable staff we'd like to keep together for an extended period of time," Wade said.
Mills, who has guided his team to a 57-46 record since starting 17-34, is thrilled to see most of the staff return for two more years.
"That's the way to do it," he said. "You talk about stability? Yes, that's what you want in an organization -- a foundation to build from. These guys are hard workers and teach the right way. They have a good foundation in the Major Leagues. Let's build on that. That just shows the sign of another thing in the right direction we're going."
Clark, who was interim manger in the final 13 games of last season, was appreciative of the two-year contract.
"I think we were all caught by surprise that they wanted to do that, but I also know they're looking at the big picture," he said. "This is a good staff they've put together. We do a real good job of working together and complimenting each other and we're really feeding off each other.
"That starts at the top with Brad Mills. That as one of the things he wanted when he came over here -- get this staff all on the same page and have fun doing it."
Bagwell, the club's all-time leader in home runs and RBIs, expects to make a decision on his future about a week after the season ends, giving the Astros time to find a replacement if he doesn't return.
"I'm a lot more happy for the coaches to get it," Bagwell said. "It's nice for me, too. I've had a great time, either yes or not whether I'll come back or not. It's been really fun and I have enjoyed it, but I'm going to have to sit down with my family and they will make the final decision."
Mills has told Bagwell he'd like to have him return.
"I've already said, 'Hey, love to have you back. I want you to do what you think is best,' but I'm a little partial," Mills said. "I'd like to have him back. He's going to have to make that decision with his family and so forth, and I totally understand that. At the same time, I really would like to see him come back. He's fit in well with the coaching staff and ballclub as well."