Exodus Travels, TrekAmerica and Grand American Adventures are extending the suspension of all their tours until August 31 as a result of the coronavirus pandemic.
The adventure tour operators and escorted tours specialists had previously put the suspension in place up to August 16.
Customers will receive an Abta-bonded Refund Credit Note, which can then be used towards any new booking made by January 31, 2021, for travel on any date up to March 31, 2022.
Refund Credit Notes can be exchanged for cash refunds by January 31, 2021, if a booking is not made by then, the companies said.
All travel agent partners with passengers booked on tours affected by this suspension are being contacted by the tour operators to discuss the available options.