The original thread has reached 50, so we will continue here. Last light posted was New London Ledge. So, next letter is "O".

Thanks to Sandy for compiling list of lights used in the first round, can't be re-used this time:
Admiralty Head, WA
Beavertail, RI
Cape Canaveral, FL
Diamond Head, HI
East Chop, MA
Forty Mile Point, MI
Grassy Island Front Range, MI
Grand Haven Inner Light, MI
Hendrick’s Head, ME
Indian Island, ME
Jupiter Inlet, FL
Kewaunee Pierhead Lighthouse, WI
Liston Front and Rear Range Lights, DE
Montauk, NY
Marinette (Menominee) North Pierhead Light, MI
New Presque Isle Light, MI
Old Presque Isle Light, MI
Pemaquid Point, ME
Queen’s Wharf, Canada
Reedy Island Rear Range, DE
San Luis Obispo, CA
Two Rivers Light, WI
Umpqua River Light, OR
Verona Beach, NY
Waugoshance Light, MI
Yerba Buena, CA
Zippo, Pocket and Purse