This is Bigfoot and Wildboy (1977-1979).
From Wikipedia:
Bigfoot and Wildboy was a live action children's television series on ABC. It began in 1977 as a part of The Krofft Supershow on Saturday mornings. Each episode was 15 minutes long, with cliffhanger endings resolved the following week. It became its own series in 1979 with twelve 30-minute episodes. There were a total of 28 episodes produced.
The series was heavily influenced by the two-part Bigfoot episodes of The Six Million Dollar Man, from the super-powered Bigfoot character to “bionic” sound effects used for Bigfoot running and leaping and the use of slow motion photography for action scenes such as throwing a giant object or uprooting a large metal fence post.
From IMDB:
Children's series about Wildboy, an orphan who was raised in the wilderness of the Pacific Northwest by the legendary Sasquatch. Wildboy and Bigfoot roamed the countryside stomping out pollution, capturing diabolical villains, and rescuing those in distress.
In the episode below, you can see a girl in a small town calling for Bigfoot's help, which prompts him to come running down from the hills. In other episodes, Wildboy is the one who calls for him.