White-marked tussock moth caterpillars were abundant during our April 2014 visit. Touch or any exposure to the little hair spines caused severe allergic reactions in several group members. Rashes appeared on back, stomach, arms, and neck. Treatment with antihistamine creams provided limited relief. Rashes lasted several days. Washing with soap and water did not help and may have spread the exposure. The hairy spines can become airborn. Also squashing bug may result in hairy spines becoming embedded in wood of picnic tables. Caterpillars drop from trees, so they are difficult to avoid. People who have asthma should be especially cautious.