The ARRL June VHF Contest is coming up this weekend - starting at 1800z on Saturday and going until Sunday evening - see details here: http://www.arrl.org/june-vhf.
The exchange is Four Digit Grid Square - http://www.arrl.org/grid-squares. The SOTA Atlas https://sotl.as/map shows Grid Square for SOTA Summits and your QRZ.com page should show it for your home address. Most GPS will show Grid Square.
There's no need to submit a log to participate - all contacts will be much appreciated by those involved in the contest.