| Country: | CRI |
| Type: | Secondary |
| Route: | 138 |
| Direction A: | West |
| Direction B: | East |
| Length Km: | 42.985 |
National Secondary Route 138, is a road between Route 4 and Route 35, contained in the north plains of the Alajuela province of Costa Rica.[1]
Starting west on Route 4, the road follows a slightly northeast direction towards Route 35. It is the main access route to the Caño Negro Wildlife Refuge. Most of the road is made of gravel, except for an asphalt segment on the west of the road.
The entire route is in Alajuela province.
In May 2020 the segment between Caño Negro Wildlife Refuge and Route 35, was asphalted for a total of 18.2km (11.3miles).[2]