The Carlsbad Caverns National Park is only about a 30 min drive from the GMNP. The two parks are actually part of the same system of mountains and therefore connected in many ways! I only had the morning to explore the park because I had to get to town later that day to run some errands (I justified this rushed action in my mind by making a promise to myself that I WILL BE BACK to take a more thoughtful/ extended visit). My game plan was to get there as close to 8AM as possible, hike the natural entrance, hike the big room loop, and then hike back up!
Driving to the Caverns wasn't too bad, but the road was narrow so I was unable to pull over to retrieve some cans I saw on the side of the road. When I got to the parking lot, it was mostly empty, but for some reason I was drawn to the back of the lot. Right when I got out I spotted a beer can in a bush next to my car! It had been calling my name!
I would say there is more of a tourist industry at Carlsbad Caverns. There is an option to not even hike down the caves, but instead to take an elevator (which is good because it's accessible to all but tough because there is a lot of foot traffic!). Connected to the visitor center there is a restaurant, and two gift shops. I had never really experienced anything like this park before, instead of hiking up a mountain you hike into the depths of the earth! I ended up taking so many dark and blurry photos of the hanging stalactites and gmites.
When walking 755 feet down into the earth your eyes begin to adjust to the lack of light. TG because I was able to spot an empty plastic water bottle behind a stone bench on my walk down! But other than that I really did not find trash along the natural entrance path to the caverns. WOOHOO!! I did find some food wrappings and paper scraps at the very bottom by the concession stand and bathroom area, but all in all not too much in the actual cave!
After leaving the caverns, I did a sweep of the visitor center and parking lot and found some plastic swords for drinks, straws, bottle caps, plastic cups, and plastic water bottles.