Garrison reads, in the Oracle:
All your actions are considered to satisfy the Rule of Presence during battles at this card's battlefield, and taking an action which attaches or transfers this card to a province is an exception to the Rule of Presence during battles at that province's battlefields.
Determined Force's second Reaction reads:
Reaction: Before the resolution of a Battle action taken by another player who controlled no units at the current battlefield when the action was announced, if none of the action's effects can move the other player's units to the current battlefield: The action's effects do not happen.
So my opponent has Garrison and Bridged Pass at the province I'm attacking. He uses Bridged Pass - can I react with Det Force? The condition is still valid in spite of Garrison, yes?