Rileys run is set in the Hidden Valley Nature Center that is located along the Santa Ana River. It has 1,500 scenic acres and 25 miles of hiking and equestrian trails. You start on a dirt pathway and turn onto the soft bike trail. This is the perfect event for first time runners to complete their goals. Part one of a three part Charity Challenge. MK5K and Run The River For The Ridge are part of the series. When all three have been completed in one calendar year you will be rewarded with a separate Charity Challenge Medal. Beautiful snow capped mountains and rolling green hills are your view. There was plenty of water and snacks and you will receive a shirt and medal for your entry. This run is organized by Riley and her friends and family to raise money for The John Ritter Foundation in hopes of continued research, treatment, and awareness of aortic health. A little chilly in the morning this year but it quickly warmed up. There are only one or two short hills in the first 3 miles and a short steeper one by mile 5. Great course to enjoy with friends.