The crash was reported around 8:30 a.m. Monday. The sheriff's department says the 27-year-old from Waukegan, Ill., wasn't wearing a seat belt.
Mentell portrayed attorney Garrett Wells on "Boston Legal" from 2005 to 2006. According to the film database IMDb.com, he also was Terrell in the 2009 Disney movie "G-Force."
The Web site says Mentell was a former member of the U.S. Junior National Speedskating team.
A message left with his agent wasn't immediately returned Tuesday.
