From Mojave Underground USA Wiki
Bloomington Cave is the fifth largest cave in Utah, at a length of 1.30 miles and a depth of 240 ft. Larger caves in Utah include Little Brush Creek Cave(5.93 miles), Big Brush Creek Cave(4.92 miles), Duck Creek Lave Tube (2.28 miles), and Main Drain Cave (1.47 miles), Bloomington Cave still contains many unmapped passages. Several thousand feet remain to be surveyed.
Bloomington Cave is a fault cave. The cave trends north and south with a western plunge of about 40 degrees. This plunge allows the cave to be descended to its maximum depth without ropes. The cave is three-dimensional fracture maze. The cave’s floor consists of large steps that are pinched off by a consistently sloping ceiling. Many of the walls turn up to be low connecting passages. At many locations the walls are indefinable. And many passages overlie each other. Many of the passages appear as if they were carbon copied at hundred of locations throughout the cave. The cave is truly a mapping nightmare!
Bloomington Cave has been known since the turn of the century with the establishment of St. George. With the city growing only miles away, this well-known cave is facing increasing vandalization. In the mid-1950s, the Utah Dixie Grotto actually dynamited the cave’s entrances shut because they believed the cave was too dangerous. The cave was quickly dug open. Spray-painted graffiti littered the walls of the heavily traveled routes. In 2005, as a large volunteer effort, large emounts of the graffiti was removed through sand blasting. In July 2009, the cave entrances' gates were completed and access was placed under a free permit system. The cave receives about 1,000 visitors/year with spring break being the heavily visitation time. See a HD youtube video of the cave at http://www.youtube.com/watch?v=m77dEbdeXCY .
Both entrances are gated. Request a free permit from the St George BLM office (435) 688-3200. The BLM limits access to 3 permits per day, so they recommend to request a permit 3 days in advance of your caving date. Groups are required to be 3 to 10 people in size. Check out http://www.blm.gov/ut/st/en/info/newsroom/2009/june/blm_to_implement_new.html for more information.
37.059059° -113.735028° @ 3700'
The cave is accessible through BLM maintained roadway off of a neighborhood street called Navajo Dr. From there, drive up Cottonwood Wash. This is a moderately harsh road that would involve the requirement of a 4WD vehicle. Alternatively, an easier route can be taken from Highway 91 that most standard cars can take, at the expense of a longer trip from nearby St. George. Take the Apex Mine road and take a left at the first mainroadway fork (a sign is present), and this will get you into coming into the Bloomington area from the west.
Please help clean up this area. Take out more than what you brought in.