In winter, take tall warm boots as the hike for the entire series and back from the parking coordinates is around 4kms.
In summer, take plenty of water and wear sun protection as the hike takes you along the south wall in direct sun and heat. Due to the bog, the mosquito population can be high.
For safety reasons, and to get the benefit of a healthy hike, I recommend you do not park along the highway to cross the ditch to the cache. In the spring and summer the ditch will be full of water, and in the winter the snow will be quite deep.
For the entire series, I recommend staying along the fence, but be careful with your footing close to the fence as there are holes to dodge, and in summer, thistles to go around.
Series Cache #4: You are looking for a non-camoflaged bison tube. After all, who in their right mind other than geocachers, and possibly city workers, would be out here anyways?