KotriSain is a small village in the Pauri Garhwal district of the Indian state of Uttarakhand. The population of KotriSain is around 500. It covers a wide geographical area, which is hilly and a valley surrounded by Corbett Tiger Reserve.

The main source of income is agriculture. The village has a primary and secondary school. Few children attend the school because of migration of citizens to nearby towns and cities like Kotdwar and sometimes further to Delhi, which is 300 kilometres (190 mi) away. Children go to Rikhnikhal/Barkhet for senior schooling.

There are few temples nearby: Dhontiyal, which is about 2 kilometres (1.2 mi) from the town, and PaniSain Nausainna Devi, located about 4 kilometres (2.5 mi) from the town. About 25 kilometres (16 mi) away, there is a famous temple called Tarkeshwar Mahadev. Kotdwar is about 80 kilometres (50 mi) from KotriSain.