Dropped car off in Columbere Estates at North End at private beach. Then drove south to the end of Columbia Lake. Turned left as you come down the last stretch of the highway after cement abutment. Make sure you look out over the weeds to see the way through them before putting your canoe in the water.
After put in - you have to go straight turn extreme right and then extreme left to get through the tall grasses. From there I paddled the west side of the Lake. The west side is safer because there are infrequent places (ever hour or so) that you could exit and with difficulty carry your canoe to the highway.
The lake alternates between quite shallow (5 feet) to modest depth 20 feet as you paddle the west. Occasionally you will come close to some idiot that will drive his powerboat too close but Columbia Lake is not very busy so it is not bad.
From end to end it was 2.25 hours with two strong paddlers. On a previous occasion with my 14-year-old son and 6-year-old son in the middle, it was 3.5 hours. This is an easy pretty paddle. The only difficulty is that if the wind comes up there are infrequent places to exit early. We say lots of fish, ducks, deer, and the occasional remote picnicking family.