No recent experience with this group, but probably the best place to look is the Houston Area Road Runners Association website (HARRA):
http://www.harra.org/ Here is the link to the groups training schedule:
http://www.harra.org/train.asp They also have a nationwide 'route finder':
http://www.harra.org/...ce=0.402665986282005 Also, this time of year several groups or organizations are holding running series to help athletes prep for the Houston Marathon so you might be able to jump in with one of the groups listed on the following webpage for a long run:
http://www.hphoustonmarathon.com/...fm?publicationID=290
¯\_(ツ)_/¯