The two environmentalists, along with PNB officials and students, planted trees of different species at a government school here, PNB spokesman S K Sharma said.
Sharma said the PNB has set a target of planting 1000 trees during this monsoon season in Uttarakhand.
Speaking on the occasion, Bahuguna called for preserving the rich ecology of the hill state and said efforts should be made to plant more trees.