Bradford was first elected to Parliament as MP for Tarawera in the 1990 election, replacing National Party colleague Ian McLean.
While still in his teens, he began a series of expeditions in his spare time, joining a party to scale Mount Taranaki in 1857, for example, and undertaking a journey in 1858 up the Mōkau River to Taupo, Lakes Rotomahana and Tarawera, the Tongariro-Ruapehu area, returning via Rangitikei and Wanganui.