Oregon Caves National Monument - Environmental Factors

Oregon Caves" past and future are inseparably tied to its water. The underground water system in the cave has created more than 15,000 feet of known cave and is still continuing to create more cave today. The water enters the cave in two ways, from Upper Cave Creek and from water within the soils above. The water level in the cave changes throughout the year. Flows are higher during the spring runoff and lower in the late summer.
The land environment above directly influences the cave environment below. Land use changes can bring about drastic effects to the cave"s water flow and aquatic ecosystem. Impacts and changes to the land such as fire suppression, altering of plant and animal species composition, and watershed management can also affect the cave environment. Further studies are needed to determine how the role of natural fire affects the cave system. The last major fire on the Monument was in 1650, with some smaller fires in 1775 and 1802. Fire has been suppressed in and around the Monument for over 100 years. This has changed the composition of the forest we see today.
Other significant natural features found on the Monument include mammalian fossils. Based on a radiocarbon date, a grizzly bear bone that was found in the cave is likely to be over 50,000 years old, making it is the oldest grizzly bear fossil ever found in North America. Jaguar bones found in the cave may date from 12,000 to 20,000 years old and are the northern-most jaguar remains in the world.