Until further notice Park Service is allowing only groups with GUIDES to hike the Los Patos - Sirena trail.
To reach the Los Patos Ranger Station, the most reasonable starting point is at the town of Guadalupe, which is four kilometers southwest of the larger town of La Palma. Until 2008, the side road ended just past Guadalupe at the point of reaching the Rincon River. During the dry season four-wheel drive vehicles have always been able to maneuver the Rincon River valley and to drive hikers as far up the river as possible, often right to the park boundary. However, high water conditions in the rainy season made this alternative unpredictable. In 2008, however, a road was built that extends considerably beyond Guadalupe and allows vehicular access much closer to the park boundary, even during the rainy season. Nevertheless, the final approach to the park boundary requires crossing the Rincon River many times, and during high water, vehicles are unlikely to be able to reach the Los Patos trailhead.
While it is always possible to hike to the trailhead, the distance from Guadalupe to the park boundary is close to seven kilometers, so for hikers intending to make the 19 km hike from the boundary to Sirena Ranger Station, it is often best to not expend energy in the approach and save strength for the main part of the hike. Also, there are twenty river crossings that are required, and these can be physically draining because of the current, the often non-trivial width of the river and uneven river bottom, and also due to the the inconvenience of having to take off and put on boots repeatedly or get one's feet wet in advance of the main part of the hike and therefore increase the likelihood of suffering from blisters.
The BEST WAY to get around all these obstacles is to rent horses at Danta Lodge in Guadalupe and to ride them to the Los Patos trailhead. Danta Lodge has twenty or so horses of their own and can procure more locally as needed. A wrangler will accompany each group and provide guidance up the Rincon River and to the trailhead and then return with the horses. I strongly recommend that all hikers entering through Los Patos plan reach the park boundary by horse.
The first map below shows the route from Danta Lodge to the Los Patos trail head in bold red. The graph to the right depicts the change in elevation along the cumulative length of the trail, revealing that over the 6.91 kilometer length of trail there is a total relief of 85 meters, indicating that the total grade of the route is 1.2%.
The complete map of the trail from Danta Lodge to the Los Patos trailhead is shown below with key features shown on the map. In the right hand column, greater descriptions are provided for each of the waypoints. The waypoints are not enumerated in the map simply to avoid a profusion of superimposed text. However, the waypoints are listed in sequential order with mileage, elevation, and brief descriptions given. Click on active portions of the route map to see the photograph taken at that point or simply view the whole set of photographs taken while traversing this route on horseback here..