John Kanode N4MM mentioned this 2018 event in a recent report, but here are more details:
“A new and exciting operating event will kick off on January 1, 2018, at 0000 UTC (New Year’s Eve in US time zones), when the ARRL International Grid Chase gets underway.
The year-long event hopes to build on the success of the highly successful 2016 National Parks on the Air (NPOTA). The objective is to work stations on any band (except 60 meters) in as many different Maidenhead grid squares as possible, and then upload your log data to ARRL’s Logbook of The World (LoTW). ” ~ from the ARRL website