Getting started. I absolutely love being in nature and it definitely has proved health benefits. I've listed the trails to my best knowledge in order of easiest and closest to St. Louis to hardest and further away. I would first recommend going to alltrails.com, or Traillink.com or Google for information on each park. Alltrails.com will give you the best GPS info on how to get to the park. It will also give you information about the trails, maps, if it's dog friendly, level of difficulty, scenery, pictures and reviews. Best advice would be to start at the beginning of the list and then work your way down.
My favorite time to hike is fall/winter because there are less bugs than in the spring/summer. With that being said, take your bug spray and wear long socks. Take a little backpack for snacks and water and make sure everyone uses the bathroom before leaving home and at the beginning of the trailhead which is where you will most likely find the bathrooms.
John F Kennedy Forest (in Forest Park)
If I'm short on time and want to be surrounded by trees for a short hike, I go to John F Kennedy in Forest Park. It's to the right of the Zoo South entrance. You can park on the street and there are smalls signs on either side of the road to enter. Very beautiful in the Fall!
Creve Couer Lake
You can walk around the lake or there is a dirt trail across the street from the lake. There are lot of mountain bikes on the trail so not really the best for kids/dogs.
Hawk Ridge Trail is pretty easy and flat. Perfect for kids.
Laumeier Sculpture Park
More of walk than a hike, but there are spots that go into the woods. Good for kids.
Cliff Cave Park
This park has had some recent upgrades. Nice views. Some paved areas and some dirt trails. Nice to have those options for when it's muddy. Parking is decent, but gets full on busy day. Two parking lots. Try the other if the first one you come to is full.
Powder Valley Conservation Nature Center
Pretty easy. Paved. Good for kids.
Rock Hollow Trail
The River Ring. Easy hike with kids. Paved, flat.
Probably most popular park to hike. Go on a day that's not crowded. Check google for nonpeak times. The Lone Wolf Trail has the best views. Little steep and rocky on the way up, but totally worth it. Take time to look at the river scenes on the way up. Dog friendly.
Babler State Park
Jefferson Barracks Park
Mississippi River Greenway - easy. More of a walk than a hike.
This is nice for families because you can drive around to view the Bison and Elk from the car and then park later to get out and enjoy a hike. Be careful to keep your distance from wildlife.
Emmenegger Nature Park
Greensfelder County Park
Great views at the overlook. At the trail entrance (to the left of the parking lot), walk up the hill and at top of the hill make a right for the overlook. Turn around and the follow the trail for the rest of the hike which will zig-zag and bring you back to the parking lot. There is also a lower trail to the right of the parking lot that takes you to a small pond with white sand. Very cool for pictures.
Lewis & Clark
Near Klondike Park. Mostly flat, easy trail for the first mile. Can go in as far as you like and then turn around or do a full loop for a longer hike.
Lime Kiln Loop Trail - I just think it's okay regarding the scenery, but I've hiked it so included on the list.
Old Chain of Rocks Bridge
Can be really windy walking across the bridge so don't go a on a windy day. The trails around there are in pretty bad shape so would recommend staying on the paved area. At Columbia Bottom Reservation Area there is a sunflower farm in the summer.
Climb the stairs and then head over across the street to the museums and the hiking trails
Pere Marquette Park
Park Outer Loop is scenic. Nice views of the river at the lookout points.
Salt Lick Point
Nice little trail on the IL side with some interesting features.
A DRIVE BUT WORTH IT
Elephant Rocks Trail
Super cute. Just short 1 mile, but you can get more activity by climbing and playing on the rocks. I would recommending hiking one of the other parks nearby.
So Pretty. Very Rocky. The signage can be a little bit lacking, so make sure you take your time and pay attention to where you are going so you make it back. I love the pictures from here.
Taum Sauk State Park
Mina Sauk Falls Trail is a little less than 3 miles. Very rocky, but the views in autumn are incredible. The actual fall is not more than a trickle unless there has been lot of recent rain. This is a for a day on the weekend where you have a lot of time b/c it's a bit of drive.
Others I haven't been too that are a drive, but I keep hearing good reviews -
Hawn State Park
Johnston Shut Ins I've been to this spot, but never hiked it. I think people go there more for getting in the water than hiking, but it's a popular note worthy place.
Don Robinson State Park
Pickle Springs Nature Area
Garden of Gods (Southern IL)
Cuivre River State Park
Shawnee National Park