The reserve is a Core Protected Area under the Guanacaste Umbrella Project. It is located on the Nicoya Peninsula on Costa Rica’s north-west coast. The reserve is managed by the Ecological Association of Paquera, Lepanto, & Cóbano (ASEPALECO), a nonprofit NGO founded in 1991, which also provides environmental education programs, a firefighter training program, a recycling center, an ecolodge, and a biological and climate research station.

The reserve is named in honor of Karen Mogensen who, with her husband Nicolas Wessberg, founded the national park system in Costa Rica.  Karen died in 1994, soon after the reserve was established.

In the 1950s and 60s, the Nicoya Peninsula had been heavily logged to make way for cattle farming, in response to the boom of the beef industry, and the virgin forest was disappearing at an alarming rate. By the 1990s, only 25% of the peninsula’s forest remained.  

Through perseverance and a strong commitment to conservation, the reserve has tripled in area to 960 hectares (2370 acres), but there is still much to be done. The loss of forests, which has accelerated to unprecedented rates in the Nicoya Peninsula in the last few years alone, has had severe consequences for wildlife. Many species struggle to find suitable habitats. The region’s native flora and fauna face a bleak future if we do not act urgently.