Say goodbye to the bar scene. Rip up those personal ads. If you live in California and are looking for a sweetheart this Valentine’s Day, look no further than — the Sierra Club. Sierra Singles, a branch of the San Francisco Bay Chapter of the national organization, is not just an environmental group; it’s also the largest activities-oriented singles club in Northern California. The group’s 1,200 members can choose from some 50 outdoor- and nature-oriented events per month, ranging from hiking, kayaking, and skiing expeditions to trash cleanups and trail maintenance, and from among sub-groups for older singles and gay and lesbian singles. Says club chair Roger Mills, “The events tend to center around outdoor activities and foster more of an appreciation of nature for the people who tend to participate.”