Twin Lakes, outside of Leadville, is one of my go to spots within a few hours of Lone Tree (Denver). While not true Alpine Lakes, the twins have crisp, clear water great for fishing, kayaking, Paddleboarding, and, if you’re brave enough, swimming! Even better, visit and walk into the old Interlocken Hotel down a short hike along the lakes, following either the Continental Divide Trail or the Colorado Trail.