Very open trail without any shade. Bring plenty of sun screen and water. The trail is not very "scenic." it follows the county line and the view is mostly neighborhoods and the creek not really a river.
There is plenty of wild life especially all types of water fowl. I also saw a family of deer at the base Red Hill trail where it intersects with Alameda Creek trail. The trail is rated as moderate and mostly due to its length. Minimum elevation change and the trail is paved. Moderate cyclist activity, then again, I went on a Thursday. Weekend activity much heavier.
Great bike ride. The path is relatively smooth and goes under all of the roads and highways. If you want to do a little extra, take a left when you reach the end and loop back through Coyote hills. There is about a mile along the sliver of land that takes you back to Coyote Hills that is rocky, so don't take that path if your tires aren't cut out for it.
Overall, a very nice ride. I parked at Isherwood Way, near Paseo Padre Pkwy. Once I parked, I noticed there are two trails along the creek. The inner trail is gravel and dirt. The outer trail is paved. I took the paved trail towards Niles Canyon. Very nice ride and pretty views. It was about 6 miles there and back to the parking lot, so I went the opposite way. Going that way was not as scenic, and had more people, but still a decent ride. Throughout the ride, I noticed several patch up work on the paved trail, so the ride wasn't very smooth. Flat ride, with the exceptions of going under the bridges, in which case you have a minor hill.
Will probably go again soon. It is good training trail for an upcoming race.