If you run or bike on the downtown hike and bike trails, you've likely already discovered the pretty but incomplete loop that circles alongside Ladybird Lake east of I-35 to Pleasant Valley rd and the Longhorn dam. But few people know that a spectacular landscape exists just beyond the dam.Beyond the Longhorn Dam and the highly controlled downtown lake is the still-flowing Lower Colorado River and a well-protected wild landscape filled with beautiful views, deer, and wild birds. These sites -- all part of the undeveloped 362 acre Roy G. Guerrero Park -- are just a couple . . .