Denver ? State game officials began releasing lynx earlier this month as part of a long-term effort to restore the native cat to Colorado.

Four lynx were released north of Wolf Creek Pass. By the end of April, a total of 37 lynx captured in Quebec and British Columbia will be released into the high-alpine forests of the San Juan Mountains.

The reintroduction program began in 1999 with the release of 41 lynx, followed by 55 more in 2000 and 33 in 2003. Up to 50 more lynx will be released in 2005, and another 15 may be released in 2006 and 2007.

Tracking crews confirmed the birth of at least 16 kittens to six lynx mothers last spring, the first time reproduction has been documented.

This winter, tracking crews confirmed that at least six of the kittens made it through the winter and are already hunting on their own. The trackers have also seen tracks and other evidence suggesting that female lynx that can no longer be tracked because their radio collars have failed may have had kittens as well.