"Things have been going really well," Mattison told Dawgman.com over the weekend. "I have offers now from Arizona State, Boise State, Colorado, Colorado State, San Jose State, Washington and Washington State and there have been a bunch of schools that have stopped by to see me workout and talk to me.
"USC watched me and said they really liked what they saw. They want me to get to their camp, so I'm looking at that.
"Stanford wants me to come to their Junior Day and then their camp which are on June 17th and 18th, so I'm going to head to those for sure.
"Other than those schools, I am looking at possibly doing the Washington camp at (the University of the) Redlands, but I haven't really figured that one out yet and Boise State is having a camp down here at Corona Centennial (High School) and I'm going to try and make that one as well."
As far as the Huskies are concerned, Mattison has been in touch with running backs coach Keith Bhonapha and the two have formed a good relationship.
"We talk, usually at least once a week, and I just keep him updated on things," Mattison noted. "They were one of the first schools that offered, so they are always going to be at the top for me, but with all of these offers coming in and other schools looking at me, I just need to take my time."
Mattison has yet to visit to Seattle to check out Washington's campus, so he said he's looking at a trip, but financially that might not be viable.
"My parents and I are looking at it," Mattison said. "I want to get up there this summer to check it out. If I do, it would probably be after camps and stuff, maybe early July, but I am not sure.
"I'm definitely going to take an official visit there when the time comes."
Mattison is still holding strong to his timeline of taking at least a few of his official visits before he will be ready to make a decision, although he admitted he may not wait until the end of his senior season to commit to a program.
"I am just looking for the right fit, both academically and athletically," Mattison said. "My relationship with the coaches will be big, but also with the players. Can I see myself being part of the program for four or five years? How do I fit in with the players? Stuff like that."
As a junior last fall, Mattison posted over 2,017 yards and 26 touchdowns.