Finding Help
There do not appear to be any fully comprehensive directory services for all types of providers. At least, not yet. These are some of the best resources available at this time. The usual search routes still apply; personal recommendations, your insurance company, your general practitioner / physician, and so on.
Online Forums
ACL Subreddit / Reddit
Have questions? Just get injured? Lost? Scared? Feeling alone with no one understanding just what this ACL thing is about? Go here.
Facebook Group
ACL + Meniscus Tear Recovery Without Surgery
Physical Therapy Organizations
American Physical Therapy Association
Not every PT org may be a part of this, but you can search for services via their ChoosePT site.
ZocDoc has a PT search area.