Help me get outside & go where my wheelchair can't go!!

Jaxon is a 5 year old with Leigh Syndrome. He loves going outside but our current wheelchair does not do well in the mountain terrain that we live in. Insurance will not pay for a stroller. Jaxon has had a rough go, before the age of 2 he had 5 life flights and 2 months in the PICU for respiratory failure. We were told he had a life expectancy of 3-5, he would never walk, talk, crawl and basically be a vegetable. He has shocked everyone. He can speak 3 words, he has learned to crawl in his own way, he loves to play ball and most recently he loves his t-ball set. He is making strides everyday and one of his favorite things to do is go outside and watch the kids and animals but we can only go so far on our property. His wheelchair is heavy and bulky and not easy to push on a dirt road. We would truly benefit from this so much!!! Thank you for your consideration!