Here is where you are and There is the dam up in Waterton Canyon some fifty miles or so from here and it's possible to hike or bike there from here on the South Platte River Trail also called The Front Range Trail and further south on the Mary Carter Trail thru Chatfield State Park and then into Waterton Canyon.
There's plenty to see along the way, the conflunces of Clear Creek, Sand Creek, Ralston Creek and the start of the Highline Canal in Waterton Canyon. All of the creeks and canal have trails that will take you to Golden, Aurora, Blunn Reservoir and Green Valley Ranch. There are also many parks, wildlife viewing oppertunities and geocaches along the way.
There are many places to access all of these trails so no need do it all at once. So lets park the vehicles and get out and do some hiking and biking and caching.