I agree 100% with all of the above comments.
BBNP is great for hiking, sightseeing, or birding, but it sucks for herping. I live here and hate that I can't even enter the park without feeling unwelcome, stowing my gear, and trading my usual walking stick (a hoe with the blade removed -great for flipping, balancing, and pulling myself up rugged terrain) for a much less functional ski pole type walking stick. Many park personnel suffer from an unfortunate and irrational bias against herpers. If I thought they'd care, I'd suggest boycotting BBNP.
The birders can stalk birds all day long, but herpers can't even slow down for a herp without being suspected of poaching. Lots of cactus is stolen from the park (I'd dare say much more than herps), yet cactus lovers can examine cacti all day long and even possess shovels and tissue (traditionally for make shift toilets -but also ideal for digging and wrapping cacti). Look at a snake too closely and you might be searched. Carry a hook and you will likely be expelled, ticketed, or worse.
There are no herps in the park that can't be found just as easily (or more easily) outside the park. Scutes are an easy target in the flats north of the Christmas Mountains.