The geography of Rio Novo tells a story of descent. In the southwest, the Serra do Cachimbo rises to 500 meters, its northern face a sharp escarpment that breaks the horizon line. From there the land steps down through the Parauari-Tropas plateau, broken hilly country between 150 and 350 meters, before flattening into the Jamanxim-Xingu depression at barely 100 meters above sea level. This drop powers the park's hydrology. Waterfalls and rapids punctuate the rivers as they cascade from the highland south to the lowland north, carving through terrain that shifts from residual tablelands to flat expanses of forest floor. The Crepori and Jamanxim rivers, both tributaries of the mighty Tapajos, drain the park's western and eastern flanks respectively.

Few places in the Amazon concentrate so much ecological variety into a single protected area. The altitude difference between the Serra do Cachimbo's summit and the northern lowlands creates at least six distinct vegetation zones. Roughly 53% of the park is open rainforest, where the canopy breaks allow light to reach the understory. Another 33% is dense rainforest, the closed-canopy jungle of popular imagination. The remaining 14% occupies a transitional zone where savanna meets seasonal forest, a biome contact area that produces unusual species assemblages. Among them lives the white-cheeked spider monkey, an endangered primate endemic to this region of southern Para. With average annual rainfall of 2,337 millimeters and temperatures hovering around 27 degrees Celsius, the park pulses with the rhythms of a wet equatorial climate.

The park exists in tension with the forces around it. Most of its streams have been contaminated by illegal mining operations that preceded the park's creation and persist despite it. Garimpeiros, wildcat gold miners, use mercury and dredging equipment that turns clear forest rivers into muddy, toxic channels. Rio Novo sits within a corridor of protected lands, but protection on paper does not always translate to protection on the ground. The park adjoins the Mundurucu Indigenous Territory to the west and the Jamanxim National Forest to the east, part of a mosaic of 18 conservation units that together cover more than 14 million hectares. Yet the BR-163 highway, which connects Cuiaba to Santarem through this region, has brought waves of loggers, ranchers, and miners who view the forest as an obstacle rather than a resource to be sustained.

Created by federal decree on 13 February 2006, Rio Novo National Park is administered by ICMBio, the Chico Mendes Institute for Biodiversity Conservation, named after the rubber tapper and activist murdered in 1988 for defending the Amazon. The park is classified as IUCN Category II, meaning it prioritizes ecosystem preservation, scientific research, and ecological tourism over resource extraction. An advisory council formed in November 2011 to guide management decisions. Visitors require special permission to enter. The park belongs to a regional network of six fully protected areas covering nearly 6.7 million hectares and twelve sustainable-use reserves covering another 7.6 million. Together they form one of the largest conservation mosaics on Earth, supported by the Amazon Region Protected Areas Program. Whether that support can outpace the pressures bearing down from illegal mining, highway expansion, and deforestation remains the defining question for Rio Novo and its neighbors.