Use the Union Park trail to get to the beginning of Union Canyon Trail. This is a good intermediate to advanced trail that is very rocky and rough in places but well worth the ride. As with many trails it offers incredible views. There is only one way in and out from the Union Park side, so one way is 3 miles and 6 miles round trip. If you come in from the Lotus Creek Campground off of 742, then you can park or camp there.