Houston Zoo opens new black bear exhibit

Belle lumbered to the top of a fallen tree trunk, rising up on her hind legs to survey the land around her.

The trees, the ponds, the caves -- they're all new to the 5-year-old American black bear, part of an expansion of her exhibit at the Houston Zoo. The expansion, which officials open to the public Friday, triples the exhibit's size to 6,000 square feet.

Belle shares the exhibit with Willow, also 5, whom zoo officials say could be her biological sister. The duo came to Houston in 2013 after they were discovered being fed by patrons of a California restaurant.

Photo: Stephanie Adams/Houston Zoo The Houston Zoo's brand-new Hamill Foundation Black Bear Exhibit...

GREAT ESCAPE: Baby Belle and Willow attempt surprising Houston Zoo escape (2013)

Zoo visitors will have a chance to come nose-to-nose with Belle and Willow thanks to the brand new glass wall covering one side of the new enclosure, which included revamped water features, climbing structures and significant amounts of shade.

Alex Stuckey covers NASA and the environment for the Houston Chronicle. You can reach her at alex.stuckey@chron.com or Twitter.com/alexdstuckey.