The season typically begins in late March — March 20 was the first day of spring — and carries through April, but this year's mud season is starting late because of the cold temperatures and threatening to stick around until past Mother's Day, National Weather Service meteorologist Tony Mignon said. Officials in the three states said they are already steeling for a bad season in which thick mud could heavily impact rural communities that rely on dirt roads. The frost was still seven feet deep into the ground earlier this month in some areas of Vermont, which will cause a lot of moisture when the thaw begins, said Scott Rogers, director of maintenance and operations for the Vermont Transportation Agency. Fifteen of New Hampshire's 18 multi-use recreational trails will be closed to motorized traffic such as all-terrain vehicles until May 23, said Amy Bassett, spokeswoman for the state's division of parks and recreation.