Yeah, gender balance is often skewed. While I'm not on the market I've noticed this with the hiking community--overall, it appears approximately balanced but most actual hikes are not. The long hikes are highly male-dominated, the short ones are rather female-dominated. I've met some women that joined specifically to look for dates--and I've never seen any of them in a group that wasn't female dominant.

Coed team sports are a great way to avoid this, since there’s necessarily a rough gender balance. Join your local ultimate frisbee summer league or whatever.