This spring, Houstonians will face a plethora of allergens. March and April will bring lots of tree pollen from birch, cottonwood, maple, mesquite, ash, pecan, oak, mulberry and some pine trees.

“I’m always really hyped up for spring either ... and I see the cottonwood flying, and I know it’s going to be a rough one,” said Aaron Tull, who also suffers from allergies.

Cottonwood Spring Oasis, located 7 miles from the park's South Entrance, served as an important place both for Cahuilla Indian Tribe and gold miners who depended upon its water. Today, visitors ...