The following information is originally an article by the leading newspaper Times of India.
(Article link (courtesy) : http://timesofindia.indiatimes.com/Ahmedabad/Gir_is_lion_of_all_sanctuaries/articleshow/3561630.cms)
"...Of four national parks and 22 sanctuaries in Gujarat, Gir in Junagadh and Nal Sarovar in Ahmedabad district top the popularity charts among visitors. The state tourism department seems to have failed to market sanctuaries in other parts.
According to official data, Gir Asiatic lion forest reserve alone has attracted 66 per cent of tourists in Gujarat and over 80 per cent of total foreign tourists visiting the state. Officials said that if the data of Nal Sarovar and Thol bird sanctuaries and Gir are put together, other sanctuaries in the state have just attracted seven per cent of the domestic tourists visiting Gujarat for wildlife tourism.
Forest officials say that the only reason why there are not many visitors at other sanctuaries is lack of infrastructure and not many people are aware that these exist.
Besides, the Devalia interpretation zone for Asiatic Lions and Sasan Gir fall in the pilgrim circuit of Somnath and Diu, for those wishing a boozing break. Officials also say that Sasan Gir is a hot favourite among Amdavadis. "Rest of the sanctuaries are isolated and it is only nature lovers from the state who visit these sanctuaries."
Bharat Pathak, conservator of forests (Junagadh) says, "A detailed analysis is required. But the immediate reasons are the popularity and good infrastructure in Sasan Gir. The other attractions are also the large variety of birds found here."
It is notable that the number of tourists to Gir is increasing every year. Which was stupendous 15% hike last year!
Read more in local language :
If curious, here is a nice resource on Asiatic Lions & Gir :