Forest Bathing
I'm a regular walker on the Nine Mile Creek trails with all their current configurations: paved, graveled, and unpaved single-track. I'd be very disappointed if these trails were widened, paved, and designed to be shared with bikes. As others have commented, it's nice, I would say essential, to have a local space to immerse in the peaceful soundscape of the creek amongst the slice of forest remaining in the creek valley. I think it is not selfish to maintain this one wild space within the city of Bloomington for walkers. Since Covid forced us all into our local parks, Nine Mile Creek has been delightfully and busily occupied by walkers of all ages.
Bikers have other highly desirable natural biking routes in the city with lots of connectivity to other regional trails. Having done a lot of mountain biking in the past, I get biker's desire to have bike trails crammed into every open space available. But there are already significant miles of trails designed for mountain bikes within the city. The Minnesota Valley State Trail, the mountain bike trail below Nine Mile Creek, can be accessed from Old Cedar Ave, Lyndale Ave, Goodrich Rd at Overlook Dr, and Bloomington Ferry. It's not necessary to provide access down Nine Mile Creek as well. The terrain within the creek corridor is especially poorly suited to single track bike trails due to its steepness and sandy soils. Although I frequently walk on other single track trails that are shared with mountain bikers, I really appreciate not having to constantly be on guard for the abrupt approach of mountain bikers when I'm craning to find a bird in the treetops. Lastly, I would suggest that Nine Mile Creek itself would be further degraded by increasing the area of non pervious surface along its corridor.
There is much to be done to protect and restore this wonderful resource. Buckthorn and garlic mustard control, replacement of steps in steep areas, managing the bluff prairie remnant, and thoughtfully restoring and protecting the creek. First do no harm.