Dan,
be careful as Parks Canada is cracking down on this. Should you get caught, you will be charged and fined.
"NATIONAL PARKS GENERAL REGULATION
Closing of Areas and Ways
36. (1) Where the superintendent deems it necessary for the prevention of any seasonal or temporary danger to persons, flora, fauna or natural objects in a Park, he may by notice in writing close to public use or traffic any area in the Park for the period he considers the danger will continue.
(2) A notice referred to in subsection (1) shall be displayed on each approach road, trail or other way of access to the area in the Park closed to public use or traffic.
(3) No person shall enter any area in a Park during the period that it is closed to public use or traffic pursuant to subsection (1) except with the permission of the superintendent.
CANADA NATIONAL PARKS ACT
Offence
24 (2) Every person who contravenes any provision of the regulations, other than a provision designated by regulations made under paragraph 16(1)(y), any condition of a permit, licence or other authorizing instrument issued under the regulations or under subsection 41.1(3) and (4), or any order or direction given by a superintendent, park warden or enforcement officer under subsection 41.1(3) or (4), is guilty of an offence and liable
(a) on conviction on indictment,
(i) in the case of an individual,
(A) for a first offence, to a fine of not more than $100,000, and
(B) for a second or subsequent offence, to a fine of not more than $200,000,
[…]
(b) on summary conviction,
(i) in the case of an individual,
(A) for a first offence, to a fine of not more than $25,000, and
(B) for a second or subsequent offence, to a fine of not more than $50,000"