There are nearly 17 miles of hiking trails - from short, easy paved paths to longer nature trails to be taken. The greatest threat to the native plant life in the area is the crowds of visitors (1.7 million) that visit each year - and keeping them on trails, as opposed to trampling plants and compacting soils when visitors leave defined paths. Add in natural erosion, and inadequately managed water runoff to the human impact and you have a recipe for degrading parts of the park severely over time.
It is more lushly planted than compared to the late 1800s. Planting of non-native Rocky Mountain juniper, Ponderosa pine, and white fir. As flammable as these particular trees are, the absence of forest fires, due to human fire suppression measures, has also contributed to its lushness.
There are invasive plants to worry about too. There are crowding ones like New Mexican Locust and Siberian Elm taking up valuable space and competing for nutrients with natives. And there's noxious weeds like Leafy spurge. field staff are also trained to look out for weeds that are invasive in other parts of the state - but are not yet found in the park – like Yellow Start thistle and Purple loosestife.
We didn't spend a lot of time there, we just walked around the paved path in the more popular walking areas (staying on the paths!). It's a stunning park. If you're ever out towards Colorado Springs, it's worth a visit.