Renton Has a Mountain?

Yes, indeed.
For those of us who like to pretend to be real hikers, Echo Mountain is the place to go. It's a tranquil uphill trail in very lush woods. When you have hiked to the top of the mountain you will be rewarded by an incredible view of Mt. Rainier and the forested parts of Maple Valley, Auburn and beyond. Walking at an average pace will get you to the top of the mountain and back in about forty five minutes.
Echo Mountain is part of an undeveloped King County Park called Spring Lake/Lake Desire Park . It is south of the Cedar River and just a 10-15 minute drive east of beautiful downtown Renton. Take the Maple Valley Highway to 196th Avenue. Turn right (i.e., south) and travel about a mile. Turn right on SE 183nd and follow the road counter-clockwise(bear right) around Spring Lake. Park at the road end. Follow the obvious trail that angles to the right and up; turn right (uphill) when the trail intersects the gravel maintenance access road. Take the Peak Trail ( you'll see a sign) to the summit at about 800 feet above sea level.
You will rarely run into other hikers, and it's a very scenic short but vigorous hike.
It's also very convenient to Aloha BBQ. So if you've just consumed 10,000 calories there and feel guilty, you can burn a few of them off by climbing this nearby mountain.