Wednesday saw a group of four walkers begin a 19-day trek around the ACT border, with the 306-kilometre journey set to last 19 days.

Setting out from the point where the Murrumbidgee River crosses the ACT border, walkers David McGill, Karen Tindall, Lisa Padzensky and Stephen Goggs will traverse the border in an anti-clockwise direction. The group - three ACT State Emergency Service volunteers and one ACT Health Directorate employee - are expected to face mixed weather for the remainder of the week, with support crews and friends monitoring their progress.

ACTSES chief officer Tony Graham wished the group well as they set out in sunny but windy conditions on day one.

''Over two years in planning has gone into preparing the group for the walk, with a significant training regime,'' he said.

''The walk is expected to take the party through some challenging terrain and will begin at the northern edge of the Woodstock Nature Reserve, Coree.''

Mr Graham said other walkers will join the group during their journey, while rangers from the Namadgi National Park and staff from the ACT Emergency Service Agency will also show their support.

''Supporting arrangements have also been planned for the border walk managed by the ACTSES,'' Mr Graham said.

''A logistics team will prepare meals and provide water, and also ensure a safety watch as the walkers venture along the ACT border.''

While the planned completion date is set for Sunday, October 20, the walkers' schedule remains flexible, depending on conditions and daily progress in sometimes difficult terrain.

Mr Graham said the ACT provided a challenging and rewarding setting for the journey.

''We are fortunate to live in a territory where such a walk can be conducted in a single undertaking and I would like to wish the party and their support crew well and to return safely.''