The Sierra de las Minas is a vast, 242,642-hectare mountain park harboring an astounding diversity of plant and animal life and encompassing a motley assortment of ecosystems, including cloud forests harboring several species of endemic conifers, as well as tropical moist forests and rainforests.
The park extends 130 kilometers eastward (it’s 30 kilometers wide) into the neighboring department of Izabal, where it meets with the lowland forests and grasslands of the Río Polochic delta. The biosphere reserve ranges in elevation from 400 to 2,400 meters and is composed mainly of cloud forests throughout its mountainous core in Baja Verapaz.
Sixty-two permanent streams have their source in the upper slopes of the biosphere reserve, making it an important watershed supplying the Motagua and Polochic Rivers. It is home to healthy populations of quetzals and jaguars, among other exotic species. Together with the adjacent Bocas del Polochic Wildlife Refuge [1], the parks account for 80 percent of Guatemala’s biodiversity.
The biosphere reserve is privately administered by Defensores de la Naturaleza, a well-known local conservation group with ties to The Nature Conservancy, among others. Although you may contact this organization for trips to the reserve, your best bet is to go via one of the local community tourism cooperatives in the villages near the park, which have trained guides who can take you on trips of a few hours or several days.
Contacting this NGO proved virtually impossible despite repeated attempts and some help from the folks at INGUAT.
Links:
[1] http://www.moon.com/destinations/guatemala/el-oriente-and-izabal/lake-izabal/near-el-estor/bocas-del-polochic-wildlife-refuge