In the present study, an economic valuation was realized by using the contingent valuation method. This was done to aid the conservation of the forest of the watershed lagoon of Tecocomulco. The municipalities of Almoloya, Apan and Tepeapulco were chosen as a case study. 266 questionnaires were applied, determined by simple random sampling and proportional sampling. The results show than the WTP average was $13.33 monthly per person. This result was obtained by the binomial logit model. The economic value for the conservation of the forest was estimated at $539111.41 monthly. 65% of the respondent are willing to pay to preserve the forest, 85% know of the benefits by forests and 88% are aware of the environmental degradation that exists in the watershed. The variables that were statistically significant at a confidence level of 95% in the determination of the WTP are: age, education, gender and knowledge about the benefits of forest.